Chemotactic Light-harvesting Dual-Lanthanide Nanomotor for Revascularization and Neuroprotection of Ischemic Stroke

Chemotactic Light-harvesting Dual-Lanthanide Nanomotor for Revascularization and Neuroprotection of Ischemic Stroke | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Chemotactic Light-harvesting Dual-Lanthanide Nanomotor for Revascularization and Neuroprotection of Ischemic Stroke Shuo Li, Mengnan Yang, Zhongyu Wei, Jing Wang, Kangxi Zhou, Kesheng Dai This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8743834/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Ischemic stroke (IS) presents a major clinical challenge due to brain damage during ischemia/hypoxia and the exacerbated inflammation resulting from the surge of reactive oxygen species (ROS) after reperfusion. Herein, a lanthanide nanomotor (LNM) therapy is reported, which is based on the understanding of chemotaxis and light capture design, and fully exploits the high concurrent functionality of Ln-MOF in IS combined therapy. The LNM nanoparticles (NPs) consist of a targeting peptide layer targeting platelets and neutrophils, and dual-Ln-MOF (Eu/Ce) nanoparticle core loaded with protein drugs, enabling them to actively target thrombi and ischemic brain regions by binding to platelets and neutrophils, thereby achieving local release of thrombolytic drugs. This process can be monitored in real time through Eu 3+ luminescence captured by light. Meanwhile, the Ce 4+ /Ce 3+ can further eliminate ROS to alleviate oxidative stress damage to neurons, thereby achieving the combined treatment strategy of revascularization and neuroprotection for IS. Systematic evidence has been provided in the IS mouse model that LNM NPs effectively accumulate in the brain ischemic area and exert therapeutic effects through thrombolysis and improvement of neurological function, providing new ideas for the medical application of lanthanide-based materials in cardiovascular/neurological fields. Ischemic stroke Dual-lanthanide metal organic framework Targeted therapy Thrombolytic therapy Neuroprotective Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Ischemic stroke (IS) refers to a syndrome caused by cerebrovascular disorders leading to impaired cerebral blood supply. With a deeper understanding of the cellular interaction mechanisms within the neurovascular unit, the definition of IS has evolved from a singular focus on vascular occlusion to emphasize organ dysfunction mediated by local ischemic hypoxia [ 1 ]. In the complex pathological process of IS, cerebral tissue hypoxia and vascular endothelial injury collectively trigger platelets (PLTs) activation and the release of inflammatory signals, thereby inducing neutrophils (NEs) infiltration into the brain parenchyma and provoking a severe immune-inflammatory response [ 2 ]. Neutrophil extracellular traps (NETs), released upon NEs activation, have been demonstrated as a key mechanism exacerbating brain tissue damage and promoting thrombotic progression [ 3 , 4 ]. During this process, a positive feedback loop forms between PLTs and NEs, playing a critical role as a pathological “accelerator”. The “inflammatory chemotaxis” mediated by this interaction not only drives immunothrombosis within the local microenvironment but also establishes a self-reinforcing vicious cycle between thrombotic progression and neuronal cell damage [ 5 ]. From a therapeutic perspective, the efficacy of IS treatment highly depends on early disease recognition and effective drug accumulation in the ischemic penumbra. The core of treatment lies in rapidly restoring cerebral blood flow perfusion and effectively mitigating secondary neuronal damage triggered by oxidative stress following reperfusion. Based on the chemotactic characteristics of cellular immune factors, the novel artificial nano-motor strategy can achieve targeted accumulation of drugs at the lesion by leveraging immune cells or their chemotactic signals [ 6 , 7 ]. Compared to traditional nanocarriers relying on passive diffusion, artificial nanomotors utilize autonomous motion capabilities to actively navigate toward target regions. This approach not only enables efficient drug delivery but also simultaneously regulates PLTs function (inhibiting aggregation) [ 8 ] and NEs activity (reducing NETs release) [ 9 ], thereby disrupting the “thrombosis-inflammation” vicious cycle and achieving precise brain therapy and neuroprotection. Among various nanomaterials, metal organic frameworks (MOFs) have emerged as an excellent platform for realizing chemotactic properties due to their precisely designable structures. As crystalline porous materials constructed through coordination bonds between organic ligands and metal ions, MOFs typically exhibit extremely high specific surface areas and tunable pore structures, enabling high-load adsorption and immobilization of therapeutic drugs through host-guest interactions or defect-induced reaction sites [ 10 , 11 ]. As an important subclass of MOFs, lanthanide-based metal-organic frameworks (Ln-MOFs) are particularly suitable for addressing the complex therapeutic needs of IS due to their highly programmable chemical structures [ 12 – 14 ]. Ln³⁺ ions, acting as strong Lewis acids, exhibit excellent affinity and selectivity during adsorption processes, enabling strong binding with biomacromolecules such as proteins, peptides, and nucleic acids. This characteristic not only facilitates the regulation of Ln-MOF’s chemotactic behavior but also provides an ideal interface for the loading and delivery of protein-based therapeutic drugs [ 15 , 16 ]. Meanwhile, Ln-MOFs inherit and enhance the inherent advantages of lanthanide ions, including long fluorescence lifetime, high color purity, large Stokes shift (e.g., Eu³⁺), and remarkable redox activity (e.g., the Ce⁴⁺/Ce³⁺ pair in cerium) [ 12 ]. The synergistic effects of these functional metal units enable Ln-MOFs to be widely applied in fluorescence imaging and antioxidant therapy [ 17 – 20 ]. The strategy based on Ln-MOFs artificial motors allows for multidimensional and precise regulation of treatment, targeting the pathological features at different stages of ischemia-reperfusion injury, such as dynamic pH fluctuations, ROS level variations, and cell cycle progression [ 21 ]. The key to the highly efficient application of Ln-MOFs in IS therapy lies in achieving dual control over both physicochemical properties and biological functions through precise molecular-level design. On one hand, fine-tuning the chemical structure of organic ligands (such as modifying the number and position of carboxyl groups) can effectively regulate the number of unsaturated metal sites, pore size, and surface charge properties in Ln-MOFs [ 22 , 23 ], thereby modulating their protein adsorption behavior. On the other hand, current Ln-MOFs face limitations in vivo fluorescence imaging, as most systems operate via UV-light-triggered ligand-lanthanide energy transfer. However, this approach is hampered by poor tissue penetration and high background autofluorescence, resulting in low signal-to-noise ratios [ 24 , 25 ]. To overcome this limitation, the post-synthetic introduction of antenna ligands capable of harvesting visible to near-infrared light has been developed as an effective strategy [ 26 , 27 ]. This approach overcomes the bottlenecks of severe scattering and limited penetration depth associated with conventional short-wavelength excitation light in biological tissues. Ultimately, it enables real-time, high-signal-to-noise optical monitoring of the accumulation and retention of Ln-MOFs in cerebral lesion areas, achieving the goal of integrated diagnosis and treatment In this work, we synthesized multifunctional Ln-MOFs using selected lanthanide ions (Eu³⁺ and Ce⁴⁺), tetracycline ligands, and benzoic acid ligand. Subsequently, the thrombolytic drug urokinase plasminogen activator (uPA) was loaded into the frameworks, and the surface was modified with targeting peptides for NEs and PLTs to construct Lanthanide nanomotor (LNM) (Fig. 1 A). As illustrated in Fig. 1 B, LNM binds activated NEs and PLTs, enabling targeted delivery to thrombus sites. In the IS microenvironment, the polymer coating decomposes and releases the drug. Furthermore, LNM also plays a unique microenvironment regulatory role throughout the treatment process of IS, eliminating ROS, avoiding oxidative stress damage and further destruction of the blood-brain barrier. LNM is designed to address current deficiencies in IS diagnosis and uPA thrombolytic therapy. Through microenvironmental modulation, it aims to alleviate ischemia-reperfusion and inflammatory injury, achieving synergistic therapeutic effects. Ultimately, it provides novel insights and methodologies for optimizing IS nanomedicine systems and facilitating clinical translation. Results and discussion Design and characterization of LNM NPs As a traditional therapeutic drug for IS, uPA is a protein drug with a molecular weight of 54k Da, which can effectively degrade the fibrin network. However, its clinical application faces limitations such as easy inactivation, short half-life, and large dosage requirements. This not only compromises the sustainability of therapeutic efficacy but may also increase vascular endothelial permeability and the risk of bleeding [28]. For Ln-MOFs, enhancing their adsorption capacity for peptides and proteins not only facilitates the conjugation of targeting peptides but also enables the effective increase of uPA drug loading, prolong its circulation time, and synergistically enhance targeted accumulation and penetration at thrombus sites, thereby significantly improving thrombolytic efficiency. To screen for the optimal protein/peptide carriers, the suitable organic and tetracycline ligands for the synthesis of MOFs were selected according to the modifying methods as previously reported [29,30], the schematic diagram of ligand screening and detailed experimental processes are described in Fig. 2A and Supplementary material. Three benzoic acid ligands, H 2 BDC, H 3 BTC, and H 4 BTEC, were selected to synthesize Ce/Eu-MOFs. Based on our previous studies, it is recognized that coordination involving a higher number of carboxyl groups tends to reduce the availability of open metal sites. Given the accessibility of Hb and LK, we selected these two proteins with significantly different scale distributions as model molecules to investigate protein adsorption. As shown in Fig. 2B, the adsorption results of hemoglobin (Hb) and lumbrokinase (LK) demonstrate that Ce/Eu-BDC with more open metal sites exhibits superior adsorption performance, indicating that chemical adsorption via open metal sites plays a dominant role in the adsorption of protein-based drugs. In the dual-Ln-MOF, Eu 3+ acts as the luminescent center. However, some drawbacks of its optical properties limit its application in biological imaging, and thus, the introduction of light-harvesting ligands is necessary to enhance its optical performance. As shown in Fig. S3, Ce/Eu-BDC obtain the characteristic emissions of Eu 3+ at 594, 614, 657 and 692 nm, which are assigned to the 5 D0- 7 FJ (J = 1–4) transitions. However, Ce/Eu-BDC can only be excited by light with a wavelength below 350 nm, which limits its application in biological systems. To address this issue, we selected tetracycline ligands with light-harvesting properties to modify the excitation wavelength and other optical characteristics of the material. As illustrated in Fig. 2C, energy is transferred from the excited state of the H₂BDC ligand to the excitation state of Eu 3+ , thereby sensitizing its luminescence. After introducing doxycycline (DC), oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) (Fig. S4) into Ce/Eu-BDC, the excitation wavelengths of the resulting Ln-MOFs exhibited a red shift (Fig. S5). Among them, Ce/Eu-BDC-DC demonstrates the strongest fluorescence, with its excitation wavelength extends to the 405–460 nm range (Figs. S5 and S6). Similarly, analogous phenomena are observed in living cells, confirming its potential for fluorescence detection in vivo (Fig. 2D). To investigate the underlying mechanism, we obtained the frontier molecular orbital information for several ligands by Multiwfn [31]. The highest occupied molecular orbital (HOMO)−lowest unoccupied molecular orbital (LUMO) energy gaps of the ligands, from smallest to largest, are DC < OTC < TC < CTC (Fig. S7). As shown in Fig. S8, MOFs synthesized through ligands with smaller HOMO-LUMO gaps show stronger fluorescence intensity, indicating that tetracycline with a small band gap is conducive to intramolecular charge transfer and fluorescence enhancement [32]. Furthermore, the results of fluorescence intensity and LUMO also demonstrate that DC with lower LUMO energy levels possess stronger light-harvesting capabilities. Thus, theoretical calculations of HOMO-LUMO provide valuable guidance for selecting tetracycline ligands to design Eu-MOFs with optimal excitation wavelength and fluorescence intensity. Finally, the final synthesis route was determined by investigating the reaction conditions, the experimental processes and results are described in Supplementary Information. As displayed in Figs. S10 and 2E, the TEM results show that Ce/Eu-BDC, Ln-MOF, and LNM NPs exhibit aggregated block structure, and their sizes are mostly distributed in the range of 200 nm. The elemental distribution results demonstrate the existence of Eu, Ce, N, and S in LNM (Fig. 2F). The X-ray photoelectron spectroscopy (XPS) spectra confirm the successful loading of DC onto the Ce/Eu-BDC because the diffraction peaks of C 1s, O 1s, N 1s, Ce 3d (Ce 3d 3/2, 904.2 eV; Ce 3d 5/2, 885.8 eV) and Eu 3d (Eu 3d 3/2, 1164.5 eV; Eu 3d 5/2, 1135.6 eV) are observed in the XPS spectrum of Ln-MOF (Fig. S11). Considering the important influence of Ce valence state on antioxidant activity, the ratio of trivalent cerium ions to tetravalent cerium ions in all samples was calculated by accumulating the corresponding peak areas [33]. All samples exhibit a mixed valence state of Ce 3+ and Ce 4+ , belonging to the category of electron shuttles [34]. Their enormous specific surface area allows a large number of Ce⁴⁺/Ce³⁺ sites to be exposed on the surface, enabling direct contact with reactants and facilitating efficient electron transfer. The calculated Ce 3+ /Ce 4+ ratios in Ce/Eu-BDC and Ln-MOF are 0.48 and 0.52, respectively (Fig. S11E). This indicates that the coordination of DC on Ce/Eu-BDC exhibits a higher Ce³⁺ content, thereby enhancing the material's antioxidant capacity. Furthermore, elemental distribution of Ln-MOF (Fig. S12) also confirms the existence of Eu, Ce, and N (N is attributed to DC). The Fourier transform infrared (FT-IR) results are shown in Fig. S13, compared to the characteristic peak of protonated carboxyl group in H 2 BDC at 1679.72 cm -1 , the shift to low wavenumber of carboxyl group peak in Ce-BDC (1651.25 cm -1 ), Ce/Eu-BDC (1671.02 cm -1 ) and LNM (1674.87 cm -1 ) proves the formation of coordination bonds between carboxyl groups in H 2 BDC and the lanthanide cation. The powder X-ray diffraction (PXRD) pattern (Fig. 2G) of LNM is almost in agreement with Ce-BDC and Ce/Eu-BDC, indicating LNM retains the crystal structure of UIO-66 [35]. As characterized by dynamic light scattering (DLS) (Fig. 2H), LNM consists of nanoparticles with an average diameter of ~ 250 nm, which exceeds the size of Ce/Eu-BDC, Ln-MOF and Ln-MOF@uPA. This size expansion is attributed to uPA immobilization within the MOF pores and subsequent surface functionalization. In addition, the characterization results of zeta potential can also demonstrate the successful immobilization of uPA and surface functionalization (Fig. 2H), and the elemental distribution of LNM in Fig. 2F also illustrates the successful binding of targeted binding proteins (S is attributed to binding protein). In vitro reactive oxygen species scavenging effects The ROS scavenging mechanism and chemotactic strategy of LNM are illustrated in Fig. 3A. The uPA loading capacity of the Ln-MOF was further investigated at the quantitative level. Fluorescein isothiocyanate isomer (FITC) labelled uPA was loaded on Ln-MOF (Fig. S14) [36]. As shown in Fig. S15, the loading efficiency of uPA onto Ln-MOF is inversely correlated with the uPA amount, achieving 94.8% at 3000 U and 83.25% at 6000 U per mg of Ln-MOF. This excellent loading efficiency is beneficial for effective thrombolysis. To demonstrate the thrombolysis effects of LNM NPs, we first examined the uPA release behavior in vitro . The released uPA in the supernatant was measured by the BCA kit at the setting time points [37]. As shown in Fig. 3B, ~40% of uPA was rapidly released after dispersion in PBS buffer with pH 6.8, followed by a slow further release, ~60% of uPA could be delivered after 3 h. In contrast, the release efficiency of uPA was significantly reduced in PBS buffer at pH 7.4. The differential release of uPA proves that the loaded uPA via electrostatic interaction can be controllably delivered by pH regulation. Thus, upon injection of LNM into mice, uPA will be released in acidic environment, and the residual Ln-MOF will contribute to subsequent neuroprotection. The antioxidant activity was determined by the DPPH method (Fig. 3C) [38]. Ce/Eu-BDC, Ln-MOF, and LNM exhibit significant antioxidant activity. The results indicate that the antioxidant capacity of Ce-BDC was effectively retained even after modification and nanoencapsulation, enabling efficient direct scavenging of ROS. PC-12 cells were utilized to establish an H 2 O 2 -induced oxidative stress model in order to investigate the antioxidant properties of LNM. As anticipated, exposure to 200 μM H 2 O 2 significantly elevated intracellular ROS levels in PC-12 cells. The viability of cell was measured using a microplate reader method, and the results demonstrated significant dose-dependent ROS reduction by LNM (Fig. 3D). Analogously, the flow cytometry results reveal that the ROS + rate of cells treated with 100 μg mL -1 NPs (44.6%), 200 μg mL -1 NPs (33.2%), and 300 μg mL -1 NPs (22.3%) groups confirm the remarkable antioxidant properties of LNM (Figs. 3E and S16). Further, the intracellular ROS level was visualized by fluorescence confocal microscopy. LNM at a concentration of 100 μg mL -1 and 300 μg mL -1 partially attenuate ROS levels in PC-12 cells. The ROS fluorescence signal in the group with LNM concentration of 500 μg mL -1 is significantly reduced (Fig. 3F). Activated PLTs and NEs targeting In recent years, multiple animal and clinical studies have identified that vascular injury can cause thrombosis, further aggravating inflammation [39]. PLTs and NEs are key contributors to thrombus formation and the progression of IS, demonstrating significant tropism toward lesion sites. Therefore, targeting peptides (NEBP and PBP) were modified on Ln-MOF@uPA to target activated PLTs and NEs (Fig. 3A) [5,40]. As shown in Fig. S17, human PLTs can be successfully activated by 0.025 U mL -1 thrombin to express CD62p. Fluorescence confocal microscopy was used to determine LNM retention on cell aggregates. There is minimal red fluorescence when LNM NPs are incubated with resting PLTs and NEs, respectively. By contrast, LNM NPs are able to significantly bind to activated PLTs and NEs, respectively (Figs. 3G and H). Seen in Fig. 3I, the red fluorescence of LNM can colocalize with blue and green fluorescence of activated cells, indicating that the nanoparticles bound exclusively to activated PLTs and NEs, but not to resting cells. These results indicate that functionalizing LNM with PLTs and NEs targeting peptides successfully confers targeting tropism, demonstrating potential for their accumulation and therapeutic action at IS lesion sites. In vitro therapeutic efficacy As shown in Fig. 4A, the schematic illustrates the process of ischemia/hypoxia-induced IS and the therapeutic mechanism of LNM. PLTs are activated by vascular injury or inflammatory stimuli, adhering and aggregating at the wound site, and releasing active substances to promote blood coagulation. This process accelerates the stabilization and growth of hemostatic plugs, ultimately leading to occlusive thrombus formation [8]. We presume that LNM can achieve vascular recanalization not only by releasing thrombolytic drugs but also through its inhibitory effect on PLTs. As displayed in Figs. 4B and S18, thrombin-induced clot retraction is attenuated in PLTs treated with Ln-MOF, uPA, and LNM. LNM has the best ability to inhibit PLTs contraction in thrombin-induced clot contraction assay. Moreover, compared with control PLTs, the aggregation in response of PLTs to agonists is reduced after addition of Ln-MOF, uPA, and LNM (Figs. 4C and D). LNM is superior to Ln-MOF and uPA in reducing PLTs aggregation, resulting in a 14.25-fold inhibition rate. To investigate the effect of LNM on thrombosis, we constructed a thrombus model based on the methods described in the literature [41]. The model was made using FeCl 3 induces mesenteric artery injury. Here, PLTs were labeled with Calcein-AM to detect PLTs delivery. After attaching a piece of filter paper soaked in 6% FeCl 3 solution to the outer wall of the mesenteric arteriole, under an inverted fluorescent microscope, the thrombus containing Calcein-labeled PLTs are visible. The results are shown in Figs. 4E and F, artery thrombus formation induced by FeCl 3 reveal that LNM group increase occlusion time (27.5 versus 14.25 min) and decrease thrombus areas. Based on the above results, the LNM exhibits excellent antithrombotic effects. Surprisingly, the Ln-MOF also demonstrated antiplatelet aggregation activity. This effect is likely attributable to the conversion of arginine within the Ln-MOF to NO by nitric oxide synthase [42], thereby inhibiting PLTs aggregation and reducing thrombus formation. Consequently, the antithrombotic effect of uPA loaded onto the LNM can be amplified, leading to enhanced efficacy. To ensure the biosafety of nanoparticles, we explored the toxicity of the Ce/Eu-BDC, Ln-MOF, and LNM, according to the results shown in Fig. S19, under different conditions of nanoparticles, the survival rate of bEnd.3 cells reach more than 85%. Furthermore, blood hemolysis is also one of the key factors affecting biocompatibility. As shown in Fig. S20, little hemolysis (lower than 7.77%) is observed even when the concentration of LNM is 150 μg mL −1 . The hemolysis rate increased to 14% when the concentration increased to 250 μg mL −1 . These results indicate that LNM shows considerably low hemolysis, as also visually confirmed by the inset images. Meanwhile, the cellular internalization of LNM in bEnd.3 cells are observed under CLSM (Fig. S21). Likewise, LNM also shows excellent cellular uptake properties in PC-12 cells (Fig. 4G). As the CLSM images revealed, strong red signals could be visualized in the cytoplasm of PC-12 cells after treatment with LNM for 5 h. The co-localization of LNM with endosomes still show high fluorescence at 8 h, suggesting the effective cellular endocytosis of LNM in PC-12 cells. In vivo therapeutic effects of LNM on IS Based on the excellent antioxidant activity, targeting capability, and antithrombotic efficacy of LNM demonstrated in vitro, we subsequently investigated their therapeutic effect on IS in vivo. Mice were randomly divided into five groups to establish MCAO model and sham-operated model [43]. After 3 hours of ischemia, the neurological behavioral dysfunction of each group of mice was evaluated using the Langha score method to determine the success of the model establishment. Then, mice in different groups were intravenously injected with saline as control, Ln-MOF, uPA, and LNM NPs according to the treatment scheme (Fig. 5A). Afterwards, at different time points after the injection of LNM, the brain and organ tissues were excised and observed using the in vivo imaging system (IVIS). As shown in Figs. 5B and S22, LNM NPs preferentially accumulate in the ischemia hemispheres rather than the normal hemispheres, which is attributed to the disruption of BBB. The fluorescence of LNM NPs in the liver and kidney increased then decreased after 6 h, indicating the liver degradation and kidney elimination clearance pathway of these materials. Furthermore, we prepared paraffin sections of brain tissue and performed hematoxylin-eosin (H&E) staining to investigate the morphological and pathological changes in ischemic brain sections at 24 h post-injection. As displayed in Fig. 5C, saline and Ln-MOF groups show disrupted cellular architecture and obvious necrotic cells. However, after treatment with LNM, the cell morphology tended to be similar to sham group, which proves the great therapeutic efficacy on the pathological changes of IS. Next, the cerebral infarct volume of MCAO mice after different treatments was characterized by staining the brain slice with 2,3,5-triphenyltetrazolium chloride (TTC). As shown in Fig. 5D, compared with the sham-operated mice, large-scale cerebral infarction is observed significantly in MCAO mice. And treatment using Ln-MOF, LNM, and uPA reduce the infarct volume to 38.9%, 24.3%, and 11.2%, respectively (Fig. S23). Quantitative results show that there is no statistically significant difference between saline and Ln-MOF groups, the cerebral infarct volume is significantly reduced in LNM groups, indicating the apparent effectiveness of designed LNM to IS. Microglia, a type of highly plastic cells with phagocytic ability in the brain, are activated after IS [44]. Activated microglia have two phenotypes, proinflammatory M1-like microglia and anti-inflammatory M2-like microglia. After IS, M1-like microglia release harmful proinflammatory cytokines to exacerbate brain damage, while M2-like microglia promote brain tissue repair by releasing anti-inflammatory cytokines. The effect of LNM on the promotion of the polarization of microglia was exploited by immunofluorescence staining, ischemic brain slices after different treatments were co-stained with Iba-1 and CD16 to mark M1-like microglia, Iba-1 and CD206 to mark M2-like microglia, respectively. As the immunofluorescence results shown, Iba-1 is highly expresses in the ischemic brain tissues after the establishment of the mice MCAO model. Notably, the amount of M1-like microglia significantly decreases in the brain sections of mice receiving LNM treatments compared to the saline group (Figs. 5E and S24). In contrast, there is no significant difference in the number of M2-like microglia in ischemic brain tissue between the different treatment groups (Fig. S25). In addition, we also evaluated whether these inflammation-associated factors could be regulated after therapy, including pro-inflammatory factors (TNF-𝛼, IL-6) and anti-inflammatory factors (CAT, GSH). As shown in Fig. 5F, compared with saline-treated group, LNM treatment significantly decreases the expression of TNF-𝛼 and IL-6, while increasing the expression of CAT and GSH, indicating a good prognosis of inflammation after IS attack. Finally, the major organs (heart, liver, spleen, lung, and kidney) were stained with H&E for histopathological analysis. The H&E staining results show that the histological morphology of the organs of treated mice is consistent with that of sham mice (Fig. S26), further illustrating the biosafety of Ln-MOF and LNM. The analysis results of blood routine test including red blood cells (RBC), white blood cells (WBC), NEs, hemoglobin (HGB), and PLT in NPs treatment group also have no significant difference compare to the sham mice (Fig. S27). Collectively, the above research results demonstrate that LNM has good biosafety and could effectively reshape the inflammatory brain microenvironment after IS and protect neuronal cells from further injury. Conclusion To meet the demand for precision medicine, researchers are committed to developing novel strategies to reduce systemic toxicity and side effects in disease treatment. The most ideal delivery system is to transport drugs to the lesion site, where the drug carrier is then degraded and metabolized in the normal physiological environment without accumulation. The development and application of nanomaterials have brought a great revolution to the field of biomedicine. Surface-modified Ln-MOFs have been widely developed as an emerging class of therapeutics for treatment because they exhibit several unique properties [ 45 ]. First, Ln-MOFs exhibit diverse diagnostic capabilities, showing potential for various image-guided therapies. Second, these nanoparticles can accommodate a large number of therapeutic drug molecules, enabling combination therapy. Third, as programmable nanomaterials, Ln-MOFs can achieve functional regulation and superposition through rational design. For instance, multifunctional Ln-MOFs can be synthesized by incorporating diverse Ln 3+ ions and ligands with specific functionalities. Notably, drug-loaded Ln-MOFs have demonstrated excellent biocompatibility while simultaneously enhancing therapeutic efficacy, highlighting the immense promise of lanthanide-based nanomaterials in biomedicine [ 46 ]. To achieve effective IS treatment, we have developed a ligand-engineered Ln-MOF nanoplatform with chemotactic properties. This strategy aims to achieve an active chemotactic effect on inflammatory lesions and thrombus by using LNM to hitch PLTs and NEs. This enhances the targeted delivery efficiency of uPA, improves thrombolytic efficacy, and reduces systemic side effects. Leveraging the ROS-scavenging capability of LNM mitigates reperfusion injury, achieving anti-inflammatory and neuroprotective effects. Furthermore, the intrinsic fluorescence of LNM allows for real-time visual monitoring of the treatment process, providing a basis for efficacy assessment and protocol adjustment. Its therapeutic effect was verified in animal model experiments, achieving satisfactory treatment results for IS. Furthermore, no damage or abnormalities were observed in the animal tissues, indicating that LNM has excellent biocompatibility. However, the application value of the multifunctional lanthanide nanoparticles still needs to be further explored. Overall, this work has pioneered a type of Ln-MOF with fluorescence, loading capacity and antioxidant properties. Its key advantages include straightforward preparation and outstanding therapeutic efficacy, adding significant depth to the development of advanced intelligent materials. The combination of the functional diversity and targeted design of Ln-MOF can meet the needs of more types of treatment strategies for diseases, expanding the application of Ln-MOF in more disease diagnosis and treatment. Materials and methods Materials Urokinase plasminogen activator (uPA), 1,4-benzenedicarboxylic acid (H 2 BDC), 1,3,5-benzenetricarboxylic acid (H 3 BTC), 1,2,4,5-benzenetetracarboxylic acid (H 4 BTEC), and (NH 4 ) 2 Ce(NO 3 ) 6 were obtained from Macklin Biochemical Co., Ltd. (Shanghai, China). Eu(NO3)3·6H2O was purchased from Energy Chemical Co., Ltd. (Shanghai, China). P-selectin binding peptide CDAEWVDVS (PBP) and neutrophil elastase binding peptide CGEAIPMSIPPEVK (NEBP) were custom synthesized at Sangon Biotech Co., Ltd. (Shanghai, China). Synthesis of Ce/Eu-BDC Ce/Eu-BDC were synthesized according to the modifying methods as previously reported [ 29 , 30 ]. Briefly, the ligand H 2 BDC (83.1 mg, 0.5 mmol) was dissolved in 3 mL of DMF, (NH 4 ) 2 Ce(NO 3 ) 6 (145 mg, 0.25 mmol) and Eu(NO 3 ) 3 ·6H 2 O (111.5 mg, 0.25 mmol) were dissolved in 1 mL of deionized water. Then the above solutions were mixed. The mixed solution was transferred to a Teflon-lined stainless steel reactor and reacted at 100°C for 1 h. Synthesis of Ln-MOF and LNM Ln-MOF was synthesized at room temperature. First, 100 µL of Ce/Eu-BDC aqueous solution (20 mg mL − 1 ), 100 µL of DC aqueous solution (10 mg mL − 1 ), and 150 µL of Arg aqueous solution (10 mg mL − 1 ) were mixed by magnetic stirring for 2 h. After the reaction, the solid precipitates were separated from the solution by centrifugation, washed with deionized water twice, and freeze-dried overnight to obtain Ln-MOF. For the preparation of LNM, different volume of uPA (1 mg mL − 1 , dissolved in 0.9% NaCl) were added to 1 mL of freshly synthesized Ln-MOF dispersion (2 mg mL − 1 in 0.9% NaCl) and stirred for 2 hours at room temperature to optimize parameters of the uPA loading. Then, 1 mL of DSPE-PEG-Mal solution (2 mg mL − 1 in deionized water) was added to the above solution and was continuously stirred for 4 hours, the solid precipitates were separated from the solution by centrifugation, washed with deionized water twice. Subsequently, 200 µL of PBP and NEBP solution (1 mg mL − 1 , dissolved in deionized water) were added to above centrifuge tube, respectively. To remove the free PBP and NEBP attached to the surface of MOF nanoparticles, the supernatant was discarded, and the solid samples were collected by centrifuge after washing with deionized water, and finally freeze-dried overnight to obtain LNM. DPPH radical scavenging test The antioxidant potential was evaluated according to the methodology based on the consumption of the radical DPPH. For this test, Eu-BDC, Ce-BDC, Ce/Eu-BDC, Ln-MOF, and LNM (1 mg mL − 1 ) were dispersed in pure ethanol to compare the antioxidant activity. 100 µL of each tested formulation was added to 1 mL of DPPH ethanolic solution (100 µg mL − 1 ) and kept in the dark. The absorption spectrum of DPPH in ethanol was measured initially after 4 h in order to evaluate the sustained activity. Therapeutic effect in MCAO mouse model MCAO mice were randomly divided into saline, Ln-MOF, uPA, and LNM groups. After reperfusion, the mice were injected intravenously with Ln-MOF (20 mg kg − 1 ), uPA (75 U g − 1 ), and LNM (20 mg kg − 1 ). Mice were sacrificed at 24 h after different treatments. Then, the cerebellum and olfactory bulb were removed. The brains were rapidly frozen at -40°C for 20 min, and sliced into 2 mm-thick coronal sections, and then incubated in 37°C away from light in 2% TTC solution for 30 min on a shaker. Finally, the brain slices were taken out and fixed with 10% neutral formaldehyde for 2 h and then photographed. The infarct brain tissue remained unstained (white part), whereas the normal brain tissue was stained red. The infart rate was quantitatively analyzed using ImageJ. The whole blood of mice from each treatment group was pooled at room temperature and centrifuged at 1000g to obtain serum. Then the detection of inflammatory factors was completed according to the manufacturer’s instructions of ELISA kit (Shanghai Enzyme-linked Biotechnology Co., Ltd.). The major organs (heart, liver, spleen, lung, and kidney) were isolated from the treatment mice and analyzed by H&E assay for biocompatibility evaluation. In addition, brains were analyzed by H&E and immunofluorescence assay for therapeutic effect evaluation. Statistical analysis Experiments were performed with at least three replicates, and all quantitative data are presented as the means ± SD. Statistical analysis was performed with Origin software. Comparison of multiple groups was performed using analysis of variance (ANOVA). Statistical significance is represented as * p < 0.05, ** p < 0.01, *** p < 0.001. Declarations Acknowledgements Not applicable. Author contributions Shuo Li: Data curation, Validation, Investigation, Software, Writing– original draft. Mengnan Yang: Conceptualization, Methodology, Writing – review and editing. Zhongyu Wei: Investigation, Writing – review and editing. Jing Wang: Formal analysis. Kangxi Zhou : Writing –review and editing. Kesheng Dai: Conceptualization, Methodology, Supervision, Funding acquisition, Writing – review and editing. Funding This study was funded supported by the National Natural Science Foundation of China (Grant nos. 82230003 and 82570169), Research Funds of Suzhou Fundamental Research Pilot Project (SSD2024057) and Natural Science Foundation of the Boxi Cultivation Program of the First Affiliated Hospital of Soochow University (BXQN2024030) for funding support. Data availability The data that support the findings of this study are available from the corresponding author upon reasonable request. Ethics approval and consent to participate Procedures that used animals were reviewed and approved by the Laboratory Animal Welfare and Ethics Committee of the first affiliated hospital of Soochow University. No. 2024162. Competing interests The authors declare no competing interests. References Xiong ZG, Zhu XM, Chu XP, Minami M, Hey J, Wei WL, et al. Neuroprotection in ischemia: blocking calcium-permeable acid-sensing ion channels. Cell 2004; 118: 687-98. Vestweber D. 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Peng Z, Cao Y, Pu H, Cao C, Yang W, Yang S, et al. Urokinase-loaded Pt quantum dot self-assembled nanoparticles for inflammation elimination and fibrinolytic thrombus therapy. Materials Chemistry Frontiers 2025; 9: 1278-1289. Yu L, Gao Z, Xu Q, Pan X, Xiao Y. A selective dual-response biosensor for tyrosinase monophenolase activity based on lanthanide metal-organic frameworks assisted boric acid-levodopa polymer dots. Biosens Bioelectron 2022; 210: 114320. Chen Z, Li Z, Tang N, Huang Y, Li S, Xu W, et al. Engineering ultra‐small cerium‐based metal–organic frameworks nanozymes for efficient antioxidative treatment of dry eye disease. Adv Funct Mater 2023; 34: 2307569. Lu T, Chen F. Multiwfn: a multifunctional wavefunction analyzer. J Comput Chem 2012; 33: 580-592. Li S, Chen Q, Xu Q, Wei Z, Shen Y, Wang H, et al. Hierarchical self-assembly molecular building blocks as intelligent nanoplatforms for ovarian cancer theranostics. Adv Sci 2024; 11: e2309547. Yu Y, Zhao X, Zheng Y, Xia D, Liu Y. Core-shell structured CeO 2 @ZIF-8 nanohybrids regulating the Ce(III)/Ce(IV) valence conversion to enhance ROS-scavenging capacity for periodontitis treatment. Biomaterials 2026; 325: 123588. Celardo I, Pedersen JZ, Traversa E, Ghibelli L. Pharmacological potential of cerium oxide nanoparticles. Nanoscale 2011; 3: 1411-20. He HH, Yuan JP, Cai PY, Wang KY, Feng L, Kirchon A, et al. Yolk-shell and hollow Zr/Ce-UiO-66 for manipulating selectivity in tandem reactions and photoreactions. J Am Chem Soc 2023; 145: 17164-17175. Wang D, Zhao Q, Qin J, Guo Y, Zhang C, Li Y. Urokinase loaded black phosphorus nanosheets for sequential thrombolysis and reactive oxygen species scavenging in ischemic stroke treatment. Biomater Sci 2022; 10: 4656-4666. Zou J, Wei G, Xiong C, Yu Y, Li S, Hu L, et al. Efficient oral insulin delivery enabled by transferrin-coated acid-resistant metal-organic framework nanoparticles. Sci Adv 2022; 8: eabm4677. Vale EP, Tavares WdS, Hafidi Z, Pérez L, Morán MdC, Martin-Pastor M, et al. Epigallocatechin-3-gallate loaded-zein nanoparticles: Molecular interaction, antioxidant, antienzimatic, hemolytic and cytotoxic activities. J Mol Liq 2024; 394: 123718. Cheng N, Zhang Y, Delaney MK, Wang C, Bai Y, Skidgel RA, et al. Targeting Gα 13 integrin interaction ameliorates systemic inflammation. Nat Commun 2021; 12: 3185. Sun M, Miyazawa K, Pendekanti T, Razmi A, Firlar E, Yang S, et al. Combination targeting of "platelets + fibrin" enhances clot anchorage efficiency of nanoparticles for vascular drug delivery. Nanoscale 2020; 12: 21255-21270. Yang M, Chen S, Li Q, Zhou K, Li Y, Sun C, et al. BAD-glucokinase axis regulates platelet activation and thrombosis. Arterioscler Thromb Vasc Biol 2025; 45: 778-791. Gawrys J, Gajecki D, Szahidewicz-Krupska E, Doroszko A. Intraplatelet L-arginine-nitric oxide metabolic pathway: from discovery to clinical implications in prevention and treatment of cardiovascular disorders. Oxid Med Cell Longev 2020; 2020: 1015908. Tang L, Yin Y, Liu H, Zhu M, Cao Y, Feng J, et al. Blood-brain barrier-penetrating and lesion-targeting nanoplatforms inspired by the pathophysiological features for synergistic ischemic stroke therapy. Adv Mater 2024; 36: e2312897. Kong J, Zou R, Chu R, Hu N, Liu J, Sun Y, et al. An ultrasmall Cu/Cu 2 O nanoparticle-based diselenide-bridged nanoplatform mediating reactive oxygen species scavenging and neuronal membrane enhancement for targeted therapy of ischemic stroke. ACS Nano 2024; 18: 4140-4158. Zhao J, Cai J, Hu J, Zhang Z, Liu YY, Pan D, et al. Biodegradable hollow MnO 2 decorated by carbon dots with cholesterol depletion capability for cascaded amplification of sono-immunotherapy. Biomaterials 2026; 325: 123559. Zhao L, Zhang W, Wu Q, Fu C, Ren X, Lv K, et al. Lanthanide europium MOF nanocomposite as the theranostic nanoplatform for microwave thermo-chemotherapy and fluorescence imaging. J Nanobiotechnol 2022; 20: 133. Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8743834","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":588616822,"identity":"e6061574-22fa-4f64-b894-07a1e185dbac","order_by":0,"name":"Shuo Li","email":"","orcid":"","institution":"First Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Shuo","middleName":"","lastName":"Li","suffix":""},{"id":588616824,"identity":"70c0f1fe-e0f4-4d9f-bf0a-fe7412e1bf51","order_by":1,"name":"Mengnan Yang","email":"","orcid":"","institution":"Suzhou Ninth People's Hospital, Suzhou Ninth Hospital Affiliated to Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Mengnan","middleName":"","lastName":"Yang","suffix":""},{"id":588616825,"identity":"907f9194-40ad-4a51-addb-4e8aa8eeb4f7","order_by":2,"name":"Zhongyu Wei","email":"","orcid":"","institution":"Shanghai Jiao Tong University","correspondingAuthor":false,"prefix":"","firstName":"Zhongyu","middleName":"","lastName":"Wei","suffix":""},{"id":588616828,"identity":"1e6e99b6-a79e-4af4-9ad6-406131d67c03","order_by":3,"name":"Jing Wang","email":"","orcid":"","institution":"First Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Wang","suffix":""},{"id":588616831,"identity":"13fbd77e-88a8-4663-b9ca-e4fdf28651ec","order_by":4,"name":"Kangxi Zhou","email":"","orcid":"","institution":"First Affiliated Hospital of Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Kangxi","middleName":"","lastName":"Zhou","suffix":""},{"id":588616833,"identity":"d079c220-de40-49d9-b072-7f7cd348c910","order_by":5,"name":"Kesheng Dai","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvUlEQVRIiWNgGAWjYBACCYYEhgMfGBgYG8AcYrUcnEGyFmYekrRItic/PGzz57BsfwPzwds8DHZ5BLVI8zwzOJzbdth4xgG2ZGsehuRiglrkJBKAWhoOJzYc4DGT5mE4kNhAWEv6h8MWfw4nzj/A/404LdISOQaHGdgOJ244wMNGnBbJnjcFB3vb0o03HmYztpxjkExYi8Tx9M0ffvyxlp13vPnhjTcVdoS1IAAziDAgXv0oGAWjYBSMAjwAABvyPud5nVWyAAAAAElFTkSuQmCC","orcid":"","institution":"First Affiliated Hospital of Soochow University","correspondingAuthor":true,"prefix":"","firstName":"Kesheng","middleName":"","lastName":"Dai","suffix":""}],"badges":[],"createdAt":"2026-01-30 17:38:55","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8743834/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8743834/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102652323,"identity":"8420d4bb-4adf-4e7a-b2ad-5c559bdbd3ad","added_by":"auto","created_at":"2026-02-14 07:20:13","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1088492,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSchematic of LNM fabrication and its targeted thrombolysis for ischemic stroke. \u003c/strong\u003eA) Schematic illustration of the preparation of LNM NPs. B) Therapeutic mechanisms of LNM NPs for precise ischemic stroke management.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/a4a05974e428371134fbd228.png"},{"id":102652326,"identity":"ebe74fe5-4f82-4dec-8721-568d9a1d175e","added_by":"auto","created_at":"2026-02-14 07:20:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":848281,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFabrication and characterization of LNM NPs.\u003c/strong\u003e A) Schematic illustration of MOF ligands selection. B) The adsorption capacity of Ce/Eu-MOF to Hb and LK. C) Simplified diagram of the excited singlet energy level (S\u003csub\u003e1\u003c/sub\u003e), excited triplet energy level (T\u003csub\u003e1\u003c/sub\u003e), and intersystem crossing (ISC) process of the ligand H\u003csub\u003e2\u003c/sub\u003eBDC and the energy transfer (ET) process from T\u003csub\u003e1\u003c/sub\u003e of H\u003csub\u003e2\u003c/sub\u003eBDC to the excited-state energy level of Eu\u003csup\u003e3+\u003c/sup\u003e. The frontier molecular orbital (the lowest unoccupied molecular orbital, LUMO) diagrams of DC, TC, OTC, and CTC. D) Fluorescent images of bEnd.3 cells after various treatments (The concentration of Ce/Eu-BDC-DC, Ce/Eu-BDC-TC, Ce/Eu-BDC-OTC, and Ce/Eu-BDC-CTC are 200 μg mL\u003csup\u003e-1\u003c/sup\u003e), λ\u003csub\u003eex \u003c/sub\u003e= 405 nm. E) Representative TEM images and F) elemental distribution of LNM NPs. G) PXRD pattern of Ce-BDC, Ce/Eu-BDC, and LNM NPs. H) Size distributions and zeta potentials of Ce/Eu-BDC, Ln-MOF, Ln-MOF@uPA, and LNM NPs.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/513f47b6e8e6998e7547706e.png"},{"id":102652327,"identity":"8f45eeb2-ef41-4228-99a7-b198981fdada","added_by":"auto","created_at":"2026-02-14 07:20:13","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1015175,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eThe scavenging ability of LNM NPs for ROS and their specific binding effects on PLTs and NEs.\u003c/strong\u003e A) Schematic diagram of the antioxidant capacity and chemotactic ability of LNM. B) Cumulative uPA release vs. time in PBS buffer (pH = 6.8 and 7.5). Error bars represent the standard deviations of three repetitive experiments. C) DPPH radical scavenging test of Eu-BDC, Ce-BDC, Ce/Eu-BDC, Ln-MOF, and LNM NPs. D) Cell viabilities of PC-12 treated with different concentrations of LNM NPs (100, 200, and 300 μg mL\u003csup\u003e-1\u003c/sup\u003e). E) Flow cytometry statistical results of ROS level in PC-12 treated with different concentrations of LNM NPs (100, 200, and 300 μg mL\u003csup\u003e-1\u003c/sup\u003e). Error bars represent the standard deviations of three repetitive experiments. F) Representative ROS images of PC-12 with LNM NPs treatments. G) Interaction of LNM with PLTs. The concentration of thrombin is 0.025 U mL\u003csup\u003e-1\u003c/sup\u003e. The concentration of LNM is 200 μg mL\u003csup\u003e-1\u003c/sup\u003e. H) Interaction of LNM with NEs. The concentration of phorbol 12-myristate 13-acetate (PMA) is 100 nM. The concentration of LNM is 200 μg mL\u003csup\u003e-1\u003c/sup\u003e. I) Interaction of LNM with PLTs and NEs. Scale bar: 25 μm.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/dad00ad596eeb469fec26bb2.png"},{"id":102748584,"identity":"fc5cf06b-fab4-4722-a863-8b385d43dda3","added_by":"auto","created_at":"2026-02-16 09:11:13","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1075688,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eValidation of the therapeutic efficacy of LNM NPs in vitro. \u003c/strong\u003eA) Mechanism diagram of the anti-inflammatory treatment process of IS by LMN. B) Clot reaction in PLTs after treatment with Ln-MOF, uPA, and LNM. C) PLTs aggregation results after treatment with Ln-MOF, uPA, and LNM. D) Statistical graph of PLTs aggregation results (*\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05, **\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.01). E) Representative images of FeCl\u003csub\u003e3\u003c/sub\u003e-induced mesenteric arteriole thrombosis after treatment with LNM. F) Statistical graph of occlusion times in mice. Error bars represent the standard deviations of three repetitive experiments. G) Fluorescent images of PC-12 cells uptake of LNM for different times. Scale bar: 25 μm.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/d8e8397d2db45c52a2d764b3.png"},{"id":102652324,"identity":"4087b470-1f61-4f23-9418-5a05d3a9097a","added_by":"auto","created_at":"2026-02-14 07:20:13","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":925720,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIn vivo therapeutic effects of the LNM NPs. \u003c/strong\u003eA) Experimental design for investigating the therapeutic effect of LNM on MCAO mice. B) The fluorescence of the brain and organs in MCAO mice atdifferent time points. C) Representative H\u0026amp;E staining images of brain tissue. Scale bar = 1.25 mm and 100 μm. D) Representative TTC staining images of brain sections in each treatment group. E) Immunostaining of CD16 (blue: DAPI; green: Iba-1; red: CD16; scale bar = 100 μm) to determine phenotype of microglia. F) Pro-inflammatory and anti-inflammatory factor levels in mice serum were measured by ELISA kits. Error bars represent the standard deviations of three repetitive experiments.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/563121fac8f40b6293cf339b.png"},{"id":105888422,"identity":"930f68ec-bccb-4867-8c60-076f2ccd3cb1","added_by":"auto","created_at":"2026-04-01 07:44:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4965353,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/d3e32fc7-9331-4e13-8e61-29fa9bf5c65e.pdf"},{"id":102652328,"identity":"5431ab27-32ee-4b3c-897d-2a31bf15e28b","added_by":"auto","created_at":"2026-02-14 07:20:14","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":6601274,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-8743834/v1/b036c3700837cdc8a36eefd2.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Chemotactic Light-harvesting Dual-Lanthanide Nanomotor for Revascularization and Neuroprotection of Ischemic Stroke","fulltext":[{"header":"Introduction","content":"\u003cp\u003eIschemic stroke (IS) refers to a syndrome caused by cerebrovascular disorders leading to impaired cerebral blood supply. With a deeper understanding of the cellular interaction mechanisms within the neurovascular unit, the definition of IS has evolved from a singular focus on vascular occlusion to emphasize organ dysfunction mediated by local ischemic hypoxia [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In the complex pathological process of IS, cerebral tissue hypoxia and vascular endothelial injury collectively trigger platelets (PLTs) activation and the release of inflammatory signals, thereby inducing neutrophils (NEs) infiltration into the brain parenchyma and provoking a severe immune-inflammatory response [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Neutrophil extracellular traps (NETs), released upon NEs activation, have been demonstrated as a key mechanism exacerbating brain tissue damage and promoting thrombotic progression [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. During this process, a positive feedback loop forms between PLTs and NEs, playing a critical role as a pathological \u0026ldquo;accelerator\u0026rdquo;. The \u0026ldquo;inflammatory chemotaxis\u0026rdquo; mediated by this interaction not only drives immunothrombosis within the local microenvironment but also establishes a self-reinforcing vicious cycle between thrombotic progression and neuronal cell damage [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. From a therapeutic perspective, the efficacy of IS treatment highly depends on early disease recognition and effective drug accumulation in the ischemic penumbra. The core of treatment lies in rapidly restoring cerebral blood flow perfusion and effectively mitigating secondary neuronal damage triggered by oxidative stress following reperfusion.\u003c/p\u003e \u003cp\u003eBased on the chemotactic characteristics of cellular immune factors, the novel artificial nano-motor strategy can achieve targeted accumulation of drugs at the lesion by leveraging immune cells or their chemotactic signals [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Compared to traditional nanocarriers relying on passive diffusion, artificial nanomotors utilize autonomous motion capabilities to actively navigate toward target regions. This approach not only enables efficient drug delivery but also simultaneously regulates PLTs function (inhibiting aggregation) [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] and NEs activity (reducing NETs release) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], thereby disrupting the \u0026ldquo;thrombosis-inflammation\u0026rdquo; vicious cycle and achieving precise brain therapy and neuroprotection. Among various nanomaterials, metal organic frameworks (MOFs) have emerged as an excellent platform for realizing chemotactic properties due to their precisely designable structures. As crystalline porous materials constructed through coordination bonds between organic ligands and metal ions, MOFs typically exhibit extremely high specific surface areas and tunable pore structures, enabling high-load adsorption and immobilization of therapeutic drugs through host-guest interactions or defect-induced reaction sites [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAs an important subclass of MOFs, lanthanide-based metal-organic frameworks (Ln-MOFs) are particularly suitable for addressing the complex therapeutic needs of IS due to their highly programmable chemical structures [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Ln\u0026sup3;⁺ ions, acting as strong Lewis acids, exhibit excellent affinity and selectivity during adsorption processes, enabling strong binding with biomacromolecules such as proteins, peptides, and nucleic acids. This characteristic not only facilitates the regulation of Ln-MOF\u0026rsquo;s chemotactic behavior but also provides an ideal interface for the loading and delivery of protein-based therapeutic drugs [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Meanwhile, Ln-MOFs inherit and enhance the inherent advantages of lanthanide ions, including long fluorescence lifetime, high color purity, large Stokes shift (e.g., Eu\u0026sup3;⁺), and remarkable redox activity (e.g., the Ce⁴⁺/Ce\u0026sup3;⁺ pair in cerium) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The synergistic effects of these functional metal units enable Ln-MOFs to be widely applied in fluorescence imaging and antioxidant therapy [\u003cspan additionalcitationids=\"CR18 CR19\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The strategy based on Ln-MOFs artificial motors allows for multidimensional and precise regulation of treatment, targeting the pathological features at different stages of ischemia-reperfusion injury, such as dynamic pH fluctuations, ROS level variations, and cell cycle progression [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe key to the highly efficient application of Ln-MOFs in IS therapy lies in achieving dual control over both physicochemical properties and biological functions through precise molecular-level design. On one hand, fine-tuning the chemical structure of organic ligands (such as modifying the number and position of carboxyl groups) can effectively regulate the number of unsaturated metal sites, pore size, and surface charge properties in Ln-MOFs [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], thereby modulating their protein adsorption behavior. On the other hand, current Ln-MOFs face limitations in vivo fluorescence imaging, as most systems operate via UV-light-triggered ligand-lanthanide energy transfer. However, this approach is hampered by poor tissue penetration and high background autofluorescence, resulting in low signal-to-noise ratios [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. To overcome this limitation, the post-synthetic introduction of antenna ligands capable of harvesting visible to near-infrared light has been developed as an effective strategy [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. This approach overcomes the bottlenecks of severe scattering and limited penetration depth associated with conventional short-wavelength excitation light in biological tissues. Ultimately, it enables real-time, high-signal-to-noise optical monitoring of the accumulation and retention of Ln-MOFs in cerebral lesion areas, achieving the goal of integrated diagnosis and treatment\u003c/p\u003e \u003cp\u003eIn this work, we synthesized multifunctional Ln-MOFs using selected lanthanide ions (Eu\u0026sup3;⁺ and Ce⁴⁺), tetracycline ligands, and benzoic acid ligand. Subsequently, the thrombolytic drug urokinase plasminogen activator (uPA) was loaded into the frameworks, and the surface was modified with targeting peptides for NEs and PLTs to construct Lanthanide nanomotor (LNM) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB, LNM binds activated NEs and PLTs, enabling targeted delivery to thrombus sites. In the IS microenvironment, the polymer coating decomposes and releases the drug. Furthermore, LNM also plays a unique microenvironment regulatory role throughout the treatment process of IS, eliminating ROS, avoiding oxidative stress damage and further destruction of the blood-brain barrier. LNM is designed to address current deficiencies in IS diagnosis and uPA thrombolytic therapy. Through microenvironmental modulation, it aims to alleviate ischemia-reperfusion and inflammatory injury, achieving synergistic therapeutic effects. Ultimately, it provides novel insights and methodologies for optimizing IS nanomedicine systems and facilitating clinical translation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003e\u003cstrong\u003eDesign and characterization of LNM NPs\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs a traditional therapeutic drug for IS, uPA is a protein drug with a molecular weight of 54k Da, which can effectively degrade the fibrin network. However, its clinical application faces limitations such as easy inactivation, short half-life, and large dosage requirements. This not only compromises the sustainability of therapeutic efficacy but may also increase vascular endothelial permeability and the risk of bleeding [28].\u003csup\u003e\u0026nbsp;\u003c/sup\u003eFor Ln-MOFs, enhancing their adsorption capacity for peptides and proteins not only facilitates the conjugation of targeting peptides but also enables the effective increase of uPA drug loading, prolong its circulation time, and synergistically enhance targeted accumulation and penetration at thrombus sites, thereby significantly improving thrombolytic efficiency. To screen for the optimal protein/peptide carriers, the suitable organic and tetracycline ligands for the synthesis of MOFs were selected according to the modifying methods as previously reported [29,30], the schematic diagram of ligand screening and detailed experimental processes are described in Fig. 2A and Supplementary material. Three benzoic acid ligands, H\u003csub\u003e2\u003c/sub\u003eBDC, H\u003csub\u003e3\u003c/sub\u003eBTC, and H\u003csub\u003e4\u003c/sub\u003eBTEC, were selected to synthesize Ce/Eu-MOFs. Based on our previous studies, it is recognized that coordination involving a higher number of carboxyl groups tends to reduce the availability of open metal sites. Given the accessibility of Hb and LK, we selected these two proteins with significantly different scale distributions as model molecules to investigate protein adsorption. As shown in Fig. 2B, the adsorption results of hemoglobin (Hb) and lumbrokinase (LK) demonstrate that Ce/Eu-BDC with more open metal sites exhibits superior adsorption performance, indicating that chemical adsorption via open metal sites plays a dominant role in the adsorption of protein-based drugs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the dual-Ln-MOF, Eu\u003csup\u003e3+\u003c/sup\u003e acts as the luminescent center. However, some drawbacks of its optical properties limit its application in biological imaging, and thus, the introduction of light-harvesting ligands is necessary to enhance its optical performance. As shown in Fig. S3, Ce/Eu-BDC obtain the characteristic emissions of Eu\u003csup\u003e3+\u003c/sup\u003e at 594, 614, 657 and 692 nm, which are assigned to the \u003csup\u003e5\u003c/sup\u003eD0-\u003csup\u003e7\u003c/sup\u003eFJ (J = 1\u0026ndash;4) transitions. However, Ce/Eu-BDC can only be excited by light with a wavelength below 350 nm, which limits its application in biological systems. To address this issue, we selected tetracycline ligands with light-harvesting properties to modify the excitation wavelength and other optical characteristics of the material. As illustrated in Fig. 2C, energy is transferred from the excited state of the H₂BDC ligand to the excitation state of Eu\u003csup\u003e3+\u003c/sup\u003e, thereby sensitizing its luminescence. After introducing doxycycline (DC), oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) (Fig. S4) into Ce/Eu-BDC, the excitation wavelengths of the resulting Ln-MOFs exhibited a red shift (Fig. S5). Among them, Ce/Eu-BDC-DC demonstrates the strongest fluorescence, with its excitation wavelength extends to the 405\u0026ndash;460 nm range (Figs. S5 and S6). Similarly, analogous phenomena are observed in living cells, confirming its potential for fluorescence detection in vivo (Fig. 2D). To investigate the underlying mechanism, we obtained the frontier molecular orbital information for several ligands by Multiwfn [31]. The highest occupied molecular orbital (HOMO)\u0026minus;lowest unoccupied molecular orbital (LUMO) energy gaps of the ligands, from smallest to largest, are DC \u0026lt; OTC \u0026lt; TC \u0026lt; CTC (Fig. S7). As shown in Fig. S8, MOFs synthesized through ligands with smaller HOMO-LUMO gaps show stronger fluorescence intensity, indicating that tetracycline with a small band gap is conducive to intramolecular charge transfer and fluorescence enhancement [32]. Furthermore, the results of fluorescence intensity and LUMO also demonstrate that DC with lower LUMO energy levels possess stronger light-harvesting capabilities. Thus, theoretical calculations of HOMO-LUMO provide valuable guidance for selecting tetracycline ligands to design Eu-MOFs with optimal excitation wavelength and fluorescence intensity. Finally, the final synthesis route was determined by investigating the reaction conditions, the experimental processes and results are described in Supplementary Information.\u003c/p\u003e\n\u003cp\u003eAs displayed in Figs. S10 and 2E, the TEM results show that Ce/Eu-BDC, Ln-MOF, and LNM NPs exhibit aggregated block structure, and their sizes are mostly distributed in the range of 200 nm. The elemental distribution results demonstrate the existence of Eu, Ce, N, and S in LNM (Fig. 2F). The X-ray photoelectron spectroscopy (XPS) spectra confirm the successful loading of DC onto the Ce/Eu-BDC because the diffraction peaks of C 1s, O 1s, N 1s, Ce 3d (Ce 3d 3/2, 904.2 eV; Ce 3d 5/2, 885.8 eV) and Eu 3d (Eu 3d 3/2, 1164.5 eV; Eu 3d 5/2, 1135.6 eV) are observed in the XPS spectrum of Ln-MOF (Fig. S11). Considering the important influence of Ce valence state on antioxidant activity, the ratio of trivalent cerium ions to tetravalent cerium ions in all samples was calculated by accumulating the corresponding peak areas [33]. All samples exhibit a mixed valence state of Ce\u003csup\u003e3+\u003c/sup\u003eand Ce\u003csup\u003e4+\u003c/sup\u003e, belonging to the category of electron shuttles [34]. Their enormous specific surface area allows a large number of Ce⁴⁺/Ce\u0026sup3;⁺ sites to be exposed on the surface, enabling direct contact with reactants and facilitating efficient electron transfer. The calculated Ce\u003csup\u003e3+\u003c/sup\u003e/Ce\u003csup\u003e4+\u003c/sup\u003e ratios in Ce/Eu-BDC and Ln-MOF are 0.48 and 0.52, respectively (Fig. S11E). This indicates that the coordination of DC on Ce/Eu-BDC exhibits a higher Ce\u0026sup3;⁺ content, thereby enhancing the material\u0026apos;s antioxidant capacity. Furthermore, elemental distribution of Ln-MOF (Fig. S12) also confirms the existence of Eu, Ce, and N (N is attributed to DC). The Fourier transform infrared (FT-IR) results are shown in Fig. S13, compared to the characteristic peak of protonated carboxyl group in H\u003csub\u003e2\u003c/sub\u003eBDC at 1679.72 cm\u003csup\u003e-1\u003c/sup\u003e, the shift to low wavenumber of carboxyl group peak in Ce-BDC (1651.25 cm\u003csup\u003e-1\u003c/sup\u003e), Ce/Eu-BDC (1671.02 cm\u003csup\u003e-1\u003c/sup\u003e) and LNM (1674.87 cm\u003csup\u003e-1\u003c/sup\u003e) proves the formation of coordination bonds between carboxyl groups in H\u003csub\u003e2\u003c/sub\u003eBDC and the lanthanide cation. The powder X-ray diffraction (PXRD) pattern (Fig. 2G) of LNM is almost in agreement with Ce-BDC and Ce/Eu-BDC, indicating LNM retains the crystal structure of UIO-66 [35]. As characterized by dynamic light scattering (DLS) (Fig. 2H), LNM consists of nanoparticles with an average diameter of ~ 250 nm, which exceeds the size of Ce/Eu-BDC, Ln-MOF and Ln-MOF@uPA. This size expansion is attributed to uPA immobilization within the MOF pores and subsequent surface functionalization. In addition, the characterization results of zeta potential can also demonstrate the successful immobilization of uPA and surface functionalization (Fig. 2H), and the elemental distribution of\u0026nbsp;LNM in Fig. 2F also illustrates the successful binding of targeted binding proteins (S is attributed to binding protein).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn vitro reactive oxygen species scavenging effects\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe ROS scavenging mechanism and chemotactic strategy of LNM are illustrated in Fig. 3A. The uPA loading capacity of the Ln-MOF was further investigated at the quantitative level. Fluorescein isothiocyanate isomer (FITC) labelled uPA was loaded on Ln-MOF (Fig. S14) [36]. As shown in Fig. S15, the loading efficiency of uPA onto Ln-MOF is inversely correlated with the uPA amount, achieving 94.8% at 3000 U and 83.25% at 6000 U per mg of Ln-MOF. This excellent loading efficiency is beneficial for effective thrombolysis. To demonstrate the thrombolysis effects of LNM NPs, we first examined the uPA release behavior \u003cem\u003ein vitro\u003c/em\u003e. The released uPA in the supernatant was measured by the BCA kit at the setting time points [37]. As shown in Fig. 3B, ~40% of uPA was rapidly released after dispersion in PBS buffer with pH 6.8, followed by a slow further release, ~60% of uPA could be delivered after 3 h. In contrast, the release efficiency of uPA was significantly reduced in PBS buffer at pH 7.4. The differential release of uPA proves that the loaded uPA via electrostatic interaction can be controllably delivered by pH regulation. Thus, upon injection of LNM into mice, uPA will be released in acidic environment, and the residual Ln-MOF will contribute to subsequent neuroprotection.\u003c/p\u003e\n\u003cp\u003eThe antioxidant activity was determined by the DPPH method (Fig. 3C) [38]. Ce/Eu-BDC, Ln-MOF, and LNM exhibit significant antioxidant activity. The results indicate that the antioxidant capacity of Ce-BDC was effectively retained even after modification and nanoencapsulation, enabling efficient direct scavenging of ROS. PC-12 cells were utilized to establish an H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e-induced oxidative stress model in order to investigate the antioxidant properties of LNM. As anticipated, exposure to 200 \u0026mu;M H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e significantly elevated intracellular ROS levels in PC-12 cells. The viability of cell was measured using a microplate reader method, and the results demonstrated significant dose-dependent ROS reduction by LNM (Fig. 3D). Analogously, the flow cytometry results reveal that the ROS\u003csup\u003e+\u003c/sup\u003e rate of cells treated with 100 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e NPs (44.6%), 200 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e NPs (33.2%), and 300 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e NPs (22.3%) groups confirm the remarkable antioxidant properties of LNM (Figs. 3E and S16). Further, the intracellular ROS level was visualized by fluorescence confocal microscopy. LNM at a concentration of 100 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e and 300 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e partially attenuate ROS levels in PC-12 cells. The ROS fluorescence signal in the group with LNM concentration of 500 \u0026mu;g mL\u003csup\u003e-1\u003c/sup\u003e is significantly reduced (Fig. 3F).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eActivated PLTs and NEs targeting\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn recent years, multiple animal and clinical studies have identified that vascular injury can cause thrombosis, further aggravating inflammation\u0026nbsp;[39]. PLTs and NEs are key contributors to thrombus formation and the progression of IS, demonstrating significant tropism toward lesion sites. Therefore, targeting peptides (NEBP and PBP) were modified on Ln-MOF@uPA to target activated PLTs and NEs (Fig. 3A) [5,40]. As shown in Fig. S17, human PLTs can be successfully activated by 0.025 U mL\u003csup\u003e-1\u003c/sup\u003e thrombin to express CD62p. Fluorescence confocal microscopy was used to determine LNM retention on cell aggregates. There is minimal red fluorescence when LNM NPs are incubated with resting PLTs and NEs, respectively. By contrast, LNM NPs are able to significantly bind to activated PLTs and NEs, respectively (Figs. 3G and H). Seen in Fig. 3I, the red fluorescence of LNM can colocalize with blue and green fluorescence of activated cells, indicating that the nanoparticles bound exclusively to activated PLTs and NEs, but not to resting cells. These results indicate that functionalizing LNM with PLTs and NEs targeting peptides successfully confers targeting tropism, demonstrating potential for their accumulation and therapeutic action at IS lesion sites.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn vitro therapeutic efficacy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in\u0026nbsp;Fig. 4A, the schematic illustrates the process of ischemia/hypoxia-induced IS and the therapeutic mechanism of LNM. PLTs are activated by vascular injury or inflammatory stimuli, adhering and aggregating at the wound site, and releasing active substances to promote blood coagulation. This process accelerates the stabilization and growth of hemostatic plugs, ultimately leading to occlusive thrombus formation\u0026nbsp;[8]. We presume that LNM can achieve vascular recanalization not only by releasing thrombolytic drugs but also through its inhibitory effect on PLTs. As displayed in Figs. 4B and S18, thrombin-induced clot retraction is attenuated in PLTs treated with Ln-MOF, uPA, and LNM. LNM has the best ability to inhibit PLTs contraction in thrombin-induced clot contraction assay. Moreover, compared with control PLTs, the aggregation in response of PLTs to agonists is reduced after addition of Ln-MOF, uPA, and LNM (Figs. 4C and D). LNM is superior to Ln-MOF and uPA in reducing PLTs aggregation, resulting in a 14.25-fold inhibition rate. To investigate the effect of LNM on thrombosis, we constructed a thrombus model based on the methods described in the literature [41]. The model was made using\u0026nbsp;FeCl\u003csub\u003e3\u003c/sub\u003e induces mesenteric artery injury. Here, PLTs were labeled with Calcein-AM to detect PLTs delivery. After attaching a piece of filter paper soaked in 6% FeCl\u003csub\u003e3\u003c/sub\u003e solution to the outer wall of the mesenteric arteriole, under an inverted fluorescent microscope, the thrombus containing Calcein-labeled PLTs are visible. The results are shown in Figs. 4E and F, artery thrombus formation induced by FeCl\u003csub\u003e3\u0026nbsp;\u003c/sub\u003ereveal that LNM group increase occlusion time (27.5 versus 14.25 min) and decrease thrombus areas. Based on the above results, the LNM exhibits excellent antithrombotic effects. Surprisingly, the Ln-MOF also demonstrated antiplatelet aggregation activity. This effect is likely attributable to the conversion of arginine within the Ln-MOF to NO by nitric oxide synthase [42], thereby inhibiting PLTs aggregation and reducing thrombus formation. Consequently, the antithrombotic effect of uPA loaded onto the LNM can be amplified, leading to enhanced efficacy.\u003c/p\u003e\n\u003cp\u003eTo ensure the biosafety of nanoparticles, we explored the toxicity of the Ce/Eu-BDC, Ln-MOF, and LNM, according to the results shown in Fig. S19, under different conditions of nanoparticles, the survival rate of bEnd.3 cells reach more than 85%. Furthermore, blood hemolysis is also one of the key factors affecting biocompatibility. As shown in Fig. S20, little hemolysis (lower than 7.77%) is observed even when the concentration of LNM is 150 \u0026mu;g mL\u003csup\u003e\u0026minus;1\u003c/sup\u003e. The hemolysis rate increased to 14% when the concentration increased to 250 \u0026mu;g mL\u003csup\u003e\u0026minus;1\u003c/sup\u003e. These results indicate that LNM shows considerably low hemolysis, as also visually confirmed by the inset images. Meanwhile, the cellular internalization of LNM in bEnd.3 cells are observed under CLSM (Fig. S21). Likewise, LNM also shows excellent cellular uptake properties in PC-12 cells (Fig. 4G). As the CLSM images revealed, strong red signals could be visualized in the cytoplasm of PC-12 cells after treatment with LNM for 5 h. The co-localization of LNM with endosomes still show high fluorescence at 8 h, suggesting the effective cellular endocytosis of LNM in PC-12 cells.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIn vivo therapeutic effects of LNM on IS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on the excellent antioxidant activity, targeting capability, and antithrombotic efficacy of LNM demonstrated in vitro, we subsequently investigated their therapeutic effect on IS in vivo. Mice were randomly divided into five groups to establish MCAO model and sham-operated model\u0026nbsp;[43]. After 3 hours of ischemia, the neurological behavioral dysfunction of each group of mice was evaluated using the Langha score method to determine the success of the model establishment. Then, mice in different groups were intravenously injected with saline as control, Ln-MOF, uPA, and LNM NPs according to the treatment scheme (Fig. 5A).\u0026nbsp;Afterwards, at different time points after the injection of LNM, the brain and organ tissues were excised and observed using the in vivo imaging system (IVIS). As shown in Figs. 5B and S22, LNM NPs preferentially accumulate in the ischemia hemispheres rather than the normal hemispheres, which\u0026nbsp;is attributed to the disruption of BBB. The fluorescence of LNM NPs in the liver and kidney increased then decreased after 6 h, indicating the liver degradation and kidney elimination clearance pathway of these materials. Furthermore,\u0026nbsp;we prepared paraffin sections of brain tissue and performed hematoxylin-eosin (H\u0026amp;E) staining to investigate the morphological and pathological changes in ischemic brain sections at 24 h post-injection. As displayed in Fig. 5C, saline and Ln-MOF groups show disrupted cellular architecture and obvious necrotic cells. However, after treatment with LNM, the cell morphology tended to be similar to sham group, which proves the great therapeutic efficacy on the pathological changes of IS. Next, the cerebral infarct volume of MCAO mice after different treatments was characterized by staining the brain slice with 2,3,5-triphenyltetrazolium chloride (TTC). As shown in Fig. 5D, compared with the sham-operated mice, large-scale cerebral infarction is observed significantly in MCAO mice. And treatment using Ln-MOF, LNM, and uPA reduce the\u0026nbsp;infarct volume to 38.9%, 24.3%, and 11.2%, respectively (Fig. S23). Quantitative results show that there is no statistically significant difference between saline and Ln-MOF groups, the cerebral infarct volume is significantly reduced in LNM groups, indicating the apparent effectiveness of designed LNM to IS.\u003c/p\u003e\n\u003cp\u003eMicroglia, a type of highly plastic cells with phagocytic ability in the brain, are activated after IS [44]. Activated microglia have two phenotypes, proinflammatory M1-like microglia and anti-inflammatory M2-like microglia. After IS, M1-like microglia release harmful proinflammatory cytokines to exacerbate brain damage, while M2-like microglia promote brain tissue repair by releasing anti-inflammatory cytokines. The effect of LNM on the promotion of the polarization of microglia was exploited by immunofluorescence staining, ischemic brain slices after different treatments were co-stained with Iba-1 and CD16 to mark M1-like microglia, Iba-1 and CD206 to mark M2-like microglia, respectively. As the immunofluorescence results shown, Iba-1 is highly expresses in the ischemic brain tissues after the establishment of the mice MCAO model. Notably, the amount of M1-like microglia significantly decreases in the brain sections of mice receiving LNM treatments compared to the saline group (Figs. 5E and S24). In contrast, there is no significant difference in the number of M2-like microglia in ischemic brain tissue between the different treatment groups (Fig. S25). In addition, we also evaluated whether these inflammation-associated factors could be regulated after therapy, including pro-inflammatory factors (TNF-𝛼, IL-6) and anti-inflammatory factors (CAT, GSH). As shown in Fig. 5F, compared with saline-treated group, LNM treatment significantly decreases the expression of TNF-𝛼 and IL-6, while increasing the expression of CAT and GSH, indicating a good prognosis of inflammation after IS attack. Finally, the major organs (heart, liver, spleen, lung, and kidney) were stained with H\u0026amp;E for histopathological analysis. The H\u0026amp;E staining results show that the histological morphology of the organs of treated mice is consistent with that of sham mice (Fig. S26), further illustrating the biosafety of Ln-MOF and LNM. The analysis results of blood routine test including red blood cells (RBC), white blood cells (WBC), NEs, hemoglobin (HGB), and PLT in NPs treatment group also have no significant difference compare to the sham mice (Fig. S27). Collectively, the above research results demonstrate that LNM has good biosafety and could effectively reshape the inflammatory brain microenvironment after IS and protect neuronal cells from further injury.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eTo meet the demand for precision medicine, researchers are committed to developing novel strategies to reduce systemic toxicity and side effects in disease treatment. The most ideal delivery system is to transport drugs to the lesion site, where the drug carrier is then degraded and metabolized in the normal physiological environment without accumulation. The development and application of nanomaterials have brought a great revolution to the field of biomedicine. Surface-modified Ln-MOFs have been widely developed as an emerging class of therapeutics for treatment because they exhibit several unique properties [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. First, Ln-MOFs exhibit diverse diagnostic capabilities, showing potential for various image-guided therapies. Second, these nanoparticles can accommodate a large number of therapeutic drug molecules, enabling combination therapy. Third, as programmable nanomaterials, Ln-MOFs can achieve functional regulation and superposition through rational design. For instance, multifunctional Ln-MOFs can be synthesized by incorporating diverse Ln\u003csup\u003e3+\u003c/sup\u003e ions and ligands with specific functionalities. Notably, drug-loaded Ln-MOFs have demonstrated excellent biocompatibility while simultaneously enhancing therapeutic efficacy, highlighting the immense promise of lanthanide-based nanomaterials in biomedicine [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo achieve effective IS treatment, we have developed a ligand-engineered Ln-MOF nanoplatform with chemotactic properties. This strategy aims to achieve an active chemotactic effect on inflammatory lesions and thrombus by using LNM to hitch PLTs and NEs. This enhances the targeted delivery efficiency of uPA, improves thrombolytic efficacy, and reduces systemic side effects. Leveraging the ROS-scavenging capability of LNM mitigates reperfusion injury, achieving anti-inflammatory and neuroprotective effects. Furthermore, the intrinsic fluorescence of LNM allows for real-time visual monitoring of the treatment process, providing a basis for efficacy assessment and protocol adjustment. Its therapeutic effect was verified in animal model experiments, achieving satisfactory treatment results for IS. Furthermore, no damage or abnormalities were observed in the animal tissues, indicating that LNM has excellent biocompatibility. However, the application value of the multifunctional lanthanide nanoparticles still needs to be further explored.\u003c/p\u003e \u003cp\u003eOverall, this work has pioneered a type of Ln-MOF with fluorescence, loading capacity and antioxidant properties. Its key advantages include straightforward preparation and outstanding therapeutic efficacy, adding significant depth to the development of advanced intelligent materials. The combination of the functional diversity and targeted design of Ln-MOF can meet the needs of more types of treatment strategies for diseases, expanding the application of Ln-MOF in more disease diagnosis and treatment.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eMaterials\u003c/h2\u003e \u003cp\u003eUrokinase plasminogen activator (uPA), 1,4-benzenedicarboxylic acid (H\u003csub\u003e2\u003c/sub\u003eBDC), 1,3,5-benzenetricarboxylic acid (H\u003csub\u003e3\u003c/sub\u003eBTC), 1,2,4,5-benzenetetracarboxylic acid (H\u003csub\u003e4\u003c/sub\u003eBTEC), and (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eCe(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003e were obtained from Macklin Biochemical Co., Ltd. (Shanghai, China). Eu(NO3)3\u0026middot;6H2O was purchased from Energy Chemical Co., Ltd. (Shanghai, China). P-selectin binding peptide CDAEWVDVS (PBP) and neutrophil elastase binding peptide CGEAIPMSIPPEVK (NEBP) were custom synthesized at Sangon Biotech Co., Ltd. (Shanghai, China).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eSynthesis of Ce/Eu-BDC\u003c/h2\u003e \u003cp\u003eCe/Eu-BDC were synthesized according to the modifying methods as previously reported [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Briefly, the ligand H\u003csub\u003e2\u003c/sub\u003eBDC (83.1 mg, 0.5 mmol) was dissolved in 3 mL of DMF, (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eCe(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e6\u003c/sub\u003e (145 mg, 0.25 mmol) and Eu(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e\u0026middot;6H\u003csub\u003e2\u003c/sub\u003eO (111.5 mg, 0.25 mmol) were dissolved in 1 mL of deionized water. Then the above solutions were mixed. The mixed solution was transferred to a Teflon-lined stainless steel reactor and reacted at 100\u0026deg;C for 1 h.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSynthesis of Ln-MOF and LNM\u003c/h2\u003e \u003cp\u003eLn-MOF was synthesized at room temperature. First, 100 \u0026micro;L of Ce/Eu-BDC aqueous solution (20 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), 100 \u0026micro;L of DC aqueous solution (10 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and 150 \u0026micro;L of Arg aqueous solution (10 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were mixed by magnetic stirring for 2 h. After the reaction, the solid precipitates were separated from the solution by centrifugation, washed with deionized water twice, and freeze-dried overnight to obtain Ln-MOF.\u003c/p\u003e \u003cp\u003eFor the preparation of LNM, different volume of uPA (1 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, dissolved in 0.9% NaCl) were added to 1 mL of freshly synthesized Ln-MOF dispersion (2 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in 0.9% NaCl) and stirred for 2 hours at room temperature to optimize parameters of the uPA loading. Then, 1 mL of DSPE-PEG-Mal solution (2 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in deionized water) was added to the above solution and was continuously stirred for 4 hours, the solid precipitates were separated from the solution by centrifugation, washed with deionized water twice. Subsequently, 200 \u0026micro;L of PBP and NEBP solution (1 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, dissolved in deionized water) were added to above centrifuge tube, respectively. To remove the free PBP and NEBP attached to the surface of MOF nanoparticles, the supernatant was discarded, and the solid samples were collected by centrifuge after washing with deionized water, and finally freeze-dried overnight to obtain LNM.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eDPPH radical scavenging test\u003c/h2\u003e \u003cp\u003eThe antioxidant potential was evaluated according to the methodology based on the consumption of the radical DPPH. For this test, Eu-BDC, Ce-BDC, Ce/Eu-BDC, Ln-MOF, and LNM (1 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were dispersed in pure ethanol to compare the antioxidant activity. 100 \u0026micro;L of each tested formulation was added to 1 mL of DPPH ethanolic solution (100 \u0026micro;g mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and kept in the dark. The absorption spectrum of DPPH in ethanol was measured initially after 4 h in order to evaluate the sustained activity.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eTherapeutic effect in MCAO mouse model\u003c/h2\u003e \u003cp\u003eMCAO mice were randomly divided into saline, Ln-MOF, uPA, and LNM groups. After reperfusion, the mice were injected intravenously with Ln-MOF (20 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), uPA (75 U g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and LNM (20 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). Mice were sacrificed at 24 h after different treatments. Then, the cerebellum and olfactory bulb were removed. The brains were rapidly frozen at -40\u0026deg;C for 20 min, and sliced into 2 mm-thick coronal sections, and then incubated in 37\u0026deg;C away from light in 2% TTC solution for 30 min on a shaker. Finally, the brain slices were taken out and fixed with 10% neutral formaldehyde for 2 h and then photographed. The infarct brain tissue remained unstained (white part), whereas the normal brain tissue was stained red. The infart rate was quantitatively analyzed using ImageJ. The whole blood of mice from each treatment group was pooled at room temperature and centrifuged at 1000g to obtain serum. Then the detection of inflammatory factors was completed according to the manufacturer\u0026rsquo;s instructions of ELISA kit (Shanghai Enzyme-linked Biotechnology Co., Ltd.). The major organs (heart, liver, spleen, lung, and kidney) were isolated from the treatment mice and analyzed by H\u0026amp;E assay for biocompatibility evaluation. In addition, brains were analyzed by H\u0026amp;E and immunofluorescence assay for therapeutic effect evaluation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eExperiments were performed with at least three replicates, and all quantitative data are presented as the means\u0026thinsp;\u0026plusmn;\u0026thinsp;SD. Statistical analysis was performed with Origin software. Comparison of multiple groups was performed using analysis of variance (ANOVA). Statistical significance is represented as \u003csup\u003e*\u003c/sup\u003e\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05, \u003csup\u003e**\u003c/sup\u003e\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.01, \u003csup\u003e***\u003c/sup\u003e\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eShuo Li:\u003c/strong\u003e Data curation, Validation, Investigation, Software, Writing\u0026ndash; original draft. \u003cstrong\u003eMengnan Yang:\u003c/strong\u003e Conceptualization, Methodology, Writing \u0026ndash; review and editing. \u003cstrong\u003eZhongyu Wei:\u003c/strong\u003e Investigation, Writing \u0026ndash; review and editing. \u003cstrong\u003eJing Wang:\u003c/strong\u003e Formal analysis. \u003cstrong\u003eKangxi Zhou\u003c/strong\u003e: Writing \u0026ndash;review and editing. \u003cstrong\u003eKesheng Dai:\u003c/strong\u003e Conceptualization, Methodology, Supervision, Funding acquisition, Writing \u0026ndash; review and editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was funded supported by the National Natural Science Foundation of China (Grant nos. 82230003 and 82570169), Research Funds of Suzhou Fundamental Research Pilot Project (SSD2024057) and Natural Science Foundation of the Boxi Cultivation Program of the First Affiliated Hospital of Soochow University (BXQN2024030) for funding support.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProcedures that used animals were reviewed and approved by the Laboratory Animal Welfare and Ethics Committee of the first affiliated hospital of Soochow University. No. 2024162.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eXiong ZG, Zhu XM, Chu XP, Minami M, Hey J, Wei WL, et al. Neuroprotection in ischemia: blocking calcium-permeable acid-sensing ion channels. Cell 2004; 118: 687-98.\u003c/li\u003e\n \u003cli\u003eVestweber D. How leukocytes cross the vascular endothelium. Nat Rev Immunol 2015; 15: 692-704.\u003c/li\u003e\n \u003cli\u003eSong J, Yang G, Song Y, Jiang Z, Jiang Y, Luan Y, et al. Neutrophil hitchhiking biomimetic nanozymes prime neuroprotective effects of ischemic stroke in a tailored \u0026ldquo;Burning the Bridges\u0026rdquo; manner. Adv Funct Mater 2024; 34: 2315275\u003c/li\u003e\n \u003cli\u003ePan J, Wang Z, Huang X, Xue J, Zhang S, Guo X, et al. 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J Nanobiotechnol 2022; 20: 133.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Ischemic stroke, Dual-lanthanide metal organic framework, Targeted therapy, Thrombolytic therapy, Neuroprotective","lastPublishedDoi":"10.21203/rs.3.rs-8743834/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8743834/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIschemic stroke (IS) presents a major clinical challenge due to brain damage during ischemia/hypoxia and the exacerbated inflammation resulting from the surge of reactive oxygen species (ROS) after reperfusion. Herein, a lanthanide nanomotor (LNM) therapy is reported, which is based on the understanding of chemotaxis and light capture design, and fully exploits the high concurrent functionality of Ln-MOF in IS combined therapy. The LNM nanoparticles (NPs) consist of a targeting peptide layer targeting platelets and neutrophils, and dual-Ln-MOF (Eu/Ce) nanoparticle core loaded with protein drugs, enabling them to actively target thrombi and ischemic brain regions by binding to platelets and neutrophils, thereby achieving local release of thrombolytic drugs. This process can be monitored in real time through Eu\u003csup\u003e3+\u003c/sup\u003e luminescence captured by light. Meanwhile, the Ce\u003csup\u003e4+\u003c/sup\u003e/Ce\u003csup\u003e3+\u003c/sup\u003e can further eliminate ROS to alleviate oxidative stress damage to neurons, thereby achieving the combined treatment strategy of revascularization and neuroprotection for IS. Systematic evidence has been provided in the IS mouse model that LNM NPs effectively accumulate in the brain ischemic area and exert therapeutic effects through thrombolysis and improvement of neurological function, providing new ideas for the medical application of lanthanide-based materials in cardiovascular/neurological fields.\u003c/p\u003e","manuscriptTitle":"Chemotactic Light-harvesting Dual-Lanthanide Nanomotor for Revascularization and Neuroprotection of Ischemic Stroke","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-14 07:20:04","doi":"10.21203/rs.3.rs-8743834/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6b6a2966-36d7-424d-8e4a-a01b797fbf84","owner":[],"postedDate":"February 14th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-01T07:43:09+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-14 07:20:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8743834","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8743834","identity":"rs-8743834","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}