Mesenchymal stem cells: opening a new chapter in the treatment of gynecological diseases

No drugs have been approved for marketing for the use of MSCs in treating gynecological diseases. As of March 16, 2025, 1,551 MSC-related studies have been registered on www.clinicaltrials.gov . There are 32 MSC-related clinical trials in gynecology, including 5 for IUA, 4 for thin endometrium, 15 for POI, 2 for PCOS, 4 for pelvic floor dysfunction, and 2 for gynecological tumors. Among the 32 studies registered on www.clinicaltrials.gov , results have been published for 8 of the m [ 169 – 178 ] ( NCT03386708 , NCT02313415 , NCT02680366 , NCT03724617 , NCT02644447 , NCT02603744 , NCT02912104 , NCT01804153 ). Additionally, findings from 2 more studies have been reported in other platforms. For comprehensive details, please consult the supplementary materials, which provide insights into the participant demographics, baseline characteristics, duration, and outcomes of these experiments.

Stem cells, often called ‘universal cells,’ possess self-renewal and multidirectional differentiation capabilities, enabling them to differentiate into various cell types and repair or regenerate damaged tissues [ 1 ]. These unique biological properties make them a valuable tool in modern medical research and treatment. Stem cells are increasingly utilized in the treatment of various diseases, offering potential cures for many previously intractable conditions through emerging therapies. Among these, mesenchymal stem cells (MSCs) play a pivotal role. MSCs are pluripotent cells widely distributed across various tissues in the human body. Initially discovered in bone marrow [ 2 ], MSCs have since been identified in a variety of tissues, including adipose tissue, umbilical cord, placenta, endometrium, and menstrual blood [ 3 ]. MSCs possess strong self-renewal capacity [ 4 ], multidirectional differentiation potential [ 5 ], immunomodulatory functions [ 6 , 7 ], low immunogenicity [ 8 ], and the ability to migrate directionally to damaged tissues [ 9 , 10 ], which positions them as the ‘seeds’ of regenerative medicine, holding promise for the treatment of various diseases [ 11 ]. Furthermore, MSCs derived from the umbilical cord, umbilical cord blood, placenta, and menstrual blood offer advantages in gynecology and obstetrics, including easy access, non-invasiveness, and fewer ethical concerns, making them a focus of regenerative medicine research [ 12 ]. In 2006, the International Society for Cellular Therapy (ISCT) established strict MSC identification standards, providing a unified reference for their research and application and enhancing the credibility of related studies [ 13 ]. The key criteria are as follows: 1. Adhesion ability: MSCs can stably attach and proliferate in plastic petri dishes. 2. Expression of specific surface markers: CD105, CD73, and CD90 must be expressed at ≥ 95%, while CD45, CD34, CD14/CD11b, CD79α/CD19, and HLA-DR must be absent, with an expression rate of < 2%. (CD45 distinguishes hematopoietic cells from non-hematopoietic cells [ 14 ], CD34 identifies hematopoietic stem cells [ 15 ], CD14/CD11b identifies macrophages [ 16 ], CD79α/CD19 identifies B-cells [ 17 ], and HLA-DR identifies antigen-presenting cells [ 18 ]) 3. Multidirectional differentiation ability: Under suitable induction conditions, MSCs must be able to differentiate into osteoblasts, adipocytes, and chondrocytes, providing the basis for their multifunctionality in disease treatment. Currently, sixteen MSC therapies have been approved worldwide: ten derived from bone marrow, three from the umbilical cord, two from adipose tissue, and one from umbilical cord blood. These therapies are used to treat conditions such as acute graft-versus-host disease, acute myocardial infarction, complex anal fistulas in Crohn’s disease, osteoarthritis, amyotrophic lateral sclerosis, and other diseases. MSCs are also widely explored in gynecology [ 19 ]. While no MSC-based therapies are currently approved, several mechanistic studies and clinical trials are underway. Gynecological diseases are highly varied, with complex and multifactorial etiologies that affect all aspects of the female reproductive system. Current MSC research in gynecology primarily focuses on intrauterine adhesion (IUA), endometriosis (EMs), primary ovarian insufficiency (POI), polycystic ovary syndrome (PCOS), pelvic floor dysfunction (including pelvic organ prolapse (POP), stress urinary incontinence (SUI), and genital fistulae), and gynecological tumors [ 20 , 21 ]. This paper reviews the mechanistic research and clinical applications of MSCs in these conditions (Fig.  1 ). Fig. 1 Sources and Applications of MSCs in Gynecology. Mesenchymal stem cells (MSCs) are extensively studied in the field of gynecology for various conditions, including primary ovarian insufficiency, intrauterine adhesion, pelvic floor dysfunction, endometriosis, polycystic ovary syndrome, and gynecological tumors. These studies primarily utilize MSCs derived from bone marrow, adipose tissue, umbilical cord or cord blood, placenta, endometrium, and menstrual blood. The schematic diagram is created with BioRender.com(Agreement number: IE28HDZZWG) Sources and Applications of MSCs in Gynecology. Mesenchymal stem cells (MSCs) are extensively studied in the field of gynecology for various conditions, including primary ovarian insufficiency, intrauterine adhesion, pelvic floor dysfunction, endometriosis, polycystic ovary syndrome, and gynecological tumors. These studies primarily utilize MSCs derived from bone marrow, adipose tissue, umbilical cord or cord blood, placenta, endometrium, and menstrual blood. The schematic diagram is created with BioRender.com(Agreement number: IE28HDZZWG)

Despite numerous breakthroughs in stem cell therapy, significant challenges remain for its advancement. The mechanisms underlying the differentiation and regulatory networks of MSCs are not yet fully understood, leading to a wide range of research findings that often contradict each other. This inconsistency not only creates uncertainty in clinical applications but also hinders the standardization of treatment protocols. Moreover, while MSCs exhibit promising biological properties in vitro, their long-term efficacy and safety in vivo require further validation through extensive clinical trials involving larger patient cohorts. A key challenge lies in the methods for large-scale production and quality control of MSCs, which are crucial to ensuring the safety and efficacy of cell therapies. This remains one of the main reasons why many research outcomes struggle to transition into clinical practice and fail to deliver effective benefits to patients. For instance, Alofisel, an allogeneic adipose-derived MSC therapy for Crohn’s disease [ 179 – 181 ], was withdrawn from the European market in December 2024 after the latest clinical trial results showed no significant difference between it and a placebo [ 182 ]. The fluctuations in Alofisel’s journey—from clinical trials to market withdrawal—are thought-provoking and highlight the urgent need for stable and efficient MSC therapies. Additionally, the high cost of MSC therapy, often reaching tens of thousands of dollars, further limits its widespread use. Developing efficient, cost-effective, and personalized therapies to benefit a larger patient population remains a significant challenge. However, the future of MSC therapy remains promising. As research continues to uncover the underlying mechanisms, this technology is expected to become safer and more efficient, potentially becoming a powerful tool for enhancing women’s health. MSCs represent not only a significant advancement in medical science but also a beacon of hope for many women suffering from gynecological diseases. They show great potential in treating infertility, refractory gynecological conditions, and cancer treatment and preservation. For example, MSC therapy has demonstrated remarkable efficacy in treating IUA and POI, offering new solutions to problems that conventional medicine has struggled to address. Looking to the future, the once ‘intractable diseases’ may eventually become a thing of the past, with MSCs playing a pivotal role in this transformation. As technology advances, the sources of MSCs will become increasingly diverse, ranging from bone marrow and adipose tissue to umbilical cord and placenta, providing more options for personalized treatment. With the continued progress of science and technology, MSCs are expected to be further optimized to better meet the individual needs of patients. We have reason to believe that MSC therapy will play a crucial role in more disease areas and bring significant benefits to patients worldwide.

Similar to other fields of study, MSC research has been conducted through both in vivo and in vitro experiments. In addition to studying the direct effects of MSCs on gynecological diseases, research also explores the exosomes they secrete [ 60 ]. Exosome-based therapies have fewer clinical trials due to challenges in quality control [ 61 ], and thus they are not the focus of this paper. MSC injections can be administered in various ways; however, without a carrier, intravenous injection of MSC suspensions results in low cell retention in the target organ [ 62 ]. As a result, many MSC studies combine these injections with different materials (Table  1 ). The following sections describe mechanistic studies of MSCs in several gynecological diseases. Table 1 MSC-Binding materials in gynecological diseases Disease Type of MSC Combined Material Authors IUA BMSCs Poly(glycerol sebacate) Xiao B et al. [ 72 ] IUA BMSCs Poly(lactic-co-glycolic acid) Xiao B et al. [ 72 ] IUA BMSCs Collagen scaffolds Xiao B et al. [ 72 ] IUA ADMSCs Autocross-linked hyaluronic acid gel Xu X et al. [ 75 ] IUA ADMSCs Methacrylate gelatin and methacrylate collagen composite hydrogel Feng M et al. [ 76 ] IUA ADMSCs Collagen scaffolds Dai Y et al. [ 77 ] IUA MenSCs Collagen scaffolds Hu X et al. [ 82 ] IUA eMSCs Human acellular amniotic membrane Xu Y et al. [ 83 ] IUA UC-MSCs Hydrogel Zhang D et al. [ 86 ] IUA UC-MSCs Collagen scaffolds Liu Y et al. [ 87 ] Gao L et al. [ 89 ] IUA UC-MSCs Matrigel microspheres Xu B et al. [ 88 ] SUI BMSCs Calcium alginate composite gel Du XW et al. [ 146 ] SUI BMSCs Degradable silk fabric scaffold for tissue-engineered sling Zou XH et al. [ 147 ] Vaginal Injury UC-MSCs Small intestine submucosa grafts Ma Y et al. [ 150 ] POP UC-MSCs Vagina-implantable electro-stimulated stem cell mesh Xiao A et al. [ 151 ] Vaginal Injury ADMSCs Gelatin scaffold Zhang G et al. [ 152 ] POP ADMSCs Tissue engineering mesh Wu X et al. [ 153 ] POP eMSCs Novel gelatin-coated polyamide scaffold Edwards SL et al. [ 154 ] MSC-Binding materials in gynecological diseases Liu Y et al. [ 87 ] Gao L et al. [ 89 ] Intrauterine adhesion (IUA), also called Asherman’s syndrome, is characterized by reduced or absent menstruation, cyclic pelvic pain, recurrent miscarriage, and infertility [ 63 , 64 ]. MSCs play a critical role in repairing the damaged endometrium [ 65 , 66 ]. The primary sources used in IUA studies are bone marrow, umbilical cord, adipose, and menstrual blood-derived MSCs. Animal models for IUA are typically established in rats by inflicting mechanical injury or using ethanol to damage the endometrium [ 67 , 68 ]. The Wnt/β-catenin signaling pathway is closely linked to fibrosis development [ 69 ]. BMSCs, in combination with estrogen, promote the differentiation of stem cells into endometrial epithelial cells, thereby facilitating the regeneration of the damaged endometrium. The underlying mechanism may involve the inhibition of epithelial-mesenchymal transition via activation of the Wnt/β-catenin signaling pathway [ 70 ]. Recently, Xiong Z et al. showed that apoptotic bodies derived from BMSCs inhibited human endometrial stromal cell fibrosis by suppressing the Wnt/β-catenin signaling pathway [ 71 ]. Blocking this pathway could offer a potential treatment for IUA. The therapeutic effects of different scaffolds loaded with BMSCs varied across studies. Poly(glycerol sebacate) (PGS) scaffolds significantly prolonged the retention time of BMSCs in the damaged rat uterus, outperforming poly(lactic-co-glycolic acid) (PLGA) and collagen scaffolds. Additionally, the PGS/BMSCs group demonstrated direct differentiation into endometrial stromal cells post-injection, promoting increased endometrial thickness, gland number, and vascular regeneration. The pregnancy rate in the PGS/BMSCs group was significantly higher than in the other groups [ 72 ]. In vivo experiments in fibrotic rats showed that electroacupuncture stimulation significantly promoted the migration of BMSCs to the injured uterus via activation of the stromal cell-derived factor-1/ CXC motif chemokine receptor 4 (SDF-1/CXCR4) axis. This treatment improved endometrial thickness, and gland number, and reduced the fibrotic area. It also decreased the expression of pro-inflammatory and fibrotic factors, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and transforming growth factor-β1 (TGF-β1), while increasing the expression of endometrial-related factors such as homeobox A10 (HoxA10) and leukocyte inhibitory factor (LIF). Moreover, it significantly increased the number of implanted embryos, enhancing uterine function recovery [ 73 ]. ADMSCs significantly improved endometrial regeneration and angiogenesis in Asherman syndrome rats by upregulating the expression of vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF-1). Additionally, miR-98 and miR-199a levels were significantly reduced in AS, but the treatment did not significantly alter their expression, indicating that the role of miRNAs in AS warrants further investigation [ 74 ]. Xu X et al. demonstrated that ADMSCs isolated and cultured from Green Fluorescent Protein (GFP) transgenic rats effectively prevented adhesion during the early stages of IUA formation. Additionally, the combination of autocross-linked hyaluronic acid (HA) gels and ADMSCs improved endometrial tolerance by modulating the expression of Smad3 and LIF [ 75 ]. ADMSCs loaded into a methacrylate gelatin (GelMA) and methacrylate collagen (ColMA) composite hydrogel also showed promising results in IUA treatment [ 76 ]. Moreover, Dai Y et al. demonstrated that ADMSC-composite collagen scaffolds (CS/ADMSC) significantly improved pregnancy and embryo implantation rates by inhibiting TGF-β1-induced fibrotic markers (e.g., collagen I, fibronectin) and α-SMA expression. They also modulated macrophage polarization, inhibited inflammatory responses, promoted endometrial stromal cell proliferation and angiogenesis, and increased endometrial thickness and gland number [ 77 ]. A recent study comparing the effects of BMSCs and ADMSCs in a rat model of Asherman syndrome found that both topical injections significantly increased endometrial thickness, outperforming intravenous ADMSCs. Topical ADMSCs were the most effective in reducing fibrosis, whereas intravenous BMSCs significantly increased VEGF expression, though the number of cells migrating to the damaged endothelium was low [ 78 ]. In IUA, an increase in Collagen I is associated with fibrosis, a decrease in cytokeratin 18 (CK18) reflects a reduction in glands, and integrin αV regulates cellular function [ 79 – 81 ]. The combination of MenSCs and CS modulates the expression of Collagen I and CK18, as well as the function of integrin αV, promoting uterine and endothelial regeneration in the long-term rat model of IUA. This significantly increased the number of glands and reduced fibrosis. Moreover, MenSCs were found to survive and function in the endometrium for up to 90 days after transplantation in the MenSCs + CS treatment group [ 82 ]. Although eMSCs are generally considered difficult to use clinically, Xu Y et al. generated multi-lineage endometrial organoids (MLEOs) by co-culturing endometrial epithelium organoids with eMSCs, and used human acellular amniotic membrane (HAAM) as a biocompatible scaffold to form a MLEO-HAAM complex. This complex was then transplanted into a rat model of endometrial injury. The MLEO-HAAM complex was found to be effective in treating AS [ 83 ]. Different injection doses and methods influence the efficacy of hUC-MSCs. In vitro experiments have shown that hUC-MSCs exert their therapeutic potential in IUA by modulating the TGF-β1/Smad3 pathway [ 84 ]. Zhang M et al. administered hUC-MSCs to IUA model rats via three routes: intraperitoneal, local, and tail vein injections, testing doses of 0.5 × 10 6 , 1 × 10 6 , and 5 × 10 6 cells. They found that intraperitoneal injection of 1 × 10 6 hUC-MSCs was the most effective regimen for IUA, promoting endometrial repair and reducing fibrosis [ 85 ]. Combining hUC-MSCs with novel materials to enhance their effects is common in studies. hUC-MSCs combined with hydrogel reduced the expression of pro-inflammatory factors (IL-1β, IL-6), increased anti-inflammatory factors (Interleukin-10 (IL-10)), modulated the inflammatory response, activated the mitogen-activated protein kinase kinase/ extracellular signal-regulated kinase 1/2 (MEK/ERK1/2) signaling pathway, induced VEGF expression, and increased embryo implantation and live birth rates. These findings highlight their potential in repairing endometrial damage and restoring fertility [ 86 ]. Liu Y et al. found that hUC-MSCs combined with collagen scaffolds reduced fibrosis and promoted endometrial repair through activation of the Hippo/TAZ signaling pathway and the SDF-1/CXCR4 axis, thereby treating IUA. This approach was more effective than hUC-MSCs or estrogen alone [ 87 ]. UC-MSCs combined with Matrigel microspheres [ 88 ] and hUC-MSCs combined with collagen scaffolds have demonstrated similar therapeutic effects [ 89 ]. In addition to hUC-MSCs used alone or combined with gel carriers, melatonin-pretreated hUC-MSCs have shown superior efficacy in treating IUA compared to hUC-MSCs alone. Melatonin-pretreated hUC-MSCs promoted endometrial regeneration and repair by modulating macrophage polarization and reducing inflammatory responses [ 90 ]. In addition to the traditional rat model, in the rabbit model, Wang JJ et al. also found that hUCB-MSCs significantly repaired endometrial injury in the IUA model by promoting endometrial glandular hyperplasia and decreasing the level of fibrosis. The mechanism may be related to inhibiting the activation of the phosphoinositide 3-kinase / protein kinase B (PI3K/AKT) signaling pathway and upregulating the expression of epidermal growth factor receptor 4, a PI3K/AKT pathway-associated anti-fibrotic molecule [ 91 ]. Overall, MSCs, either alone or in combination with certain materials, can promote endometrial glandular and vascular proliferation, alleviate inflammatory responses, reduce fibrosis, improve endometrial damage, and restore endometrial function in IUA through various mechanisms. MSCs can undoubtedly be used to treat IUA (Fig.  2 ). Fig. 2 Therapeutic Mechanisms of MSCs in IUA. Mesenchymal stem cells (MSCs) from bone marrow, adipose tissue, umbilical cord, and menstrual blood are key for intrauterine adhesion (IUA) repair. BMSCs regulate SDF-1/CXCR4 and Wnt/β-catenin pathways, reducing inflammatory factors (e.g., TGF-β1, IL-1β) and promoting VEGF, HoxA10, and LIF. ADMSCs modulate TGF-β1/Smad3, shift macrophages from M1 to M2, and increase LIF, VEGF, and IGF-1. UC-MSCs regulate multiple pathways (e.g., Hippo/TAZ, PI3K/AKT), enhance M2 macrophage polarization, and upregulate IL-10 and VEGF. MenSCs repair IUA by downregulating Collagen I and upregulating CK18 and Integrin-αV. The schematic diagram is created with BioRender.com(Agreement number: RF28G51SW3) Therapeutic Mechanisms of MSCs in IUA. Mesenchymal stem cells (MSCs) from bone marrow, adipose tissue, umbilical cord, and menstrual blood are key for intrauterine adhesion (IUA) repair. BMSCs regulate SDF-1/CXCR4 and Wnt/β-catenin pathways, reducing inflammatory factors (e.g., TGF-β1, IL-1β) and promoting VEGF, HoxA10, and LIF. ADMSCs modulate TGF-β1/Smad3, shift macrophages from M1 to M2, and increase LIF, VEGF, and IGF-1. UC-MSCs regulate multiple pathways (e.g., Hippo/TAZ, PI3K/AKT), enhance M2 macrophage polarization, and upregulate IL-10 and VEGF. MenSCs repair IUA by downregulating Collagen I and upregulating CK18 and Integrin-αV. The schematic diagram is created with BioRender.com(Agreement number: RF28G51SW3) Endometriosis (EMs) is a major disease that impacts women’s reproductive health, with key symptoms including progressive dysmenorrhea, chronic pelvic pain, deep painful intercourse, and infertility [ 92 ]. Although endometriosis is a benign condition, it exhibits malignant behavior and is considered a chronic systemic disease [ 93 ]. The role of MSCs in endometriosis is complex, as the stem cell theory is one of the proposed mechanisms for its pathogenesis [ 94 ], with eMSCs playing a significant role. Some studies suggest that macrophages produce cytokines, growth factors, and angiogenic factors that influence eMSCs, thereby promoting the development of endometriosis. Additionally, eMSCs may attract macrophages to the endometriotic lesions by secreting chemokines [ 95 ]. Research on MenSCs is increasing, and they are more readily available compared to eMSCs. One study demonstrated a significant upregulation of genes related to stem cell properties, apoptosis, migration, invasion, inflammation, and angiogenesis in endometriosis patients (E-MenSCs) by comparing gene expression between menstrual blood stem cells from E-MenSCs and healthy women. Inflammation-related genes, such as IL-1β, IL-6, IL-8, IL-10, IFN-γ, and NF-κB, showed significantly increased expression in E-MenSCs [ 96 , 97 ]. BMSCs may contribute to the progression of endometriosis, potentially by secreting nutritional factors that promote the proliferation of endometriotic cells and upregulating the expression of cyclin-dependent kinase 1, thereby facilitating lesion growth [ 98 ]. Another hypothesis suggests that endometriotic lesions may induce the differentiation of BMDCs and the expression of programmed death-1 through the CXCL12/CXCR4 signaling pathway, further promoting lesion development and immune evasion [ 99 ]. Furthermore, a study by Zhang W et al. demonstrated that in endometriosis, 17β-estradiol enhances the chemotaxis and migration of BMSCs by increasing the secretion of chemokines, particularly SDF-1α [ 100 ]. Although BMSCs may promote the development of endometriotic lesions, a study by Dwiningsih SR et al. found that BMSC transplantation in a mouse model of endometriosis reduced the expression of tumor necrosis factor-α receptor 1 (TNFα-R1), decreased granulocyte apoptosis, and improved follicle formation [ 101 ]. In contrast to BMSCs, ADMSCs suppress endometriosis through immune modulation. Meligy FY et al. pointed out that ADMSCs treatment significantly reduced the number of CD68-positive macrophages in the endometriosis mouse model and decreased the expression of pro-inflammatory cytokines (such as interferon-γ (IFNγ), TNF-α, and IL-1β), while enhancing the expression of the anti-inflammatory cytokine IL-10, but had no significant effect on IL-6 [ 102 ]. Hirakawa T et al. also found that early-passage ADMSCs significantly inhibited the growth of endometriotic lesions, reduced the thickness of the stromal fibrosis in the lesions, and suppressed the proliferation of endometriotic epithelial cells. However, late-passage ADMSCs showed no significant effect [ 103 ]. Moreover, they observed that ADMSCs treatment significantly reduced the expression of pro-inflammatory factors (such as IL-6, monocyte chemoattractant protein-1(MCP-1), and LIF) and pro-fibrotic factors (such as TGF-β1), but had no significant impact on anti-inflammatory factors (such as IL-4, IL-10), matrix metalloproteinases (such as matrix metalloproteinase-2(MMP2), MMP9), angiogenesis factors (such as vascular endothelial growth factor A (VEGFA)) or hormone receptors (such as estrogen receptor 1 (ER1), progesterone receptor (PGR)) [ 103 ]. It has been found that hUC-MSCs can significantly reduce nerve fiber density in endometriotic lesions, which may have a positive effect on alleviating endometriosis-related pain, though the exact mechanism remains unclear [ 104 ]. In a macaque model of spontaneous endometriosis, intraperitoneal injection of hUC-MSCs exacerbated the symptoms of endometriosis, whereas intravenous injection of UC-MSCs had a limited ameliorative effect on the lesions, although it did lower the CA125 level [ 105 ]. These results suggest that UC-MSCs may worsen endometriosis through paracrine effects, and thus, the use of intraperitoneal injections of UC-MSCs for treating this condition is not recommended. Additionally, an in vitro study found that the conditioned medium and cell-free lysate of human umbilical cord Wharton’s jelly stem cells were able to inhibit the viability and proliferation of endometriotic cells by inducing apoptosis and decreasing the expression of MMP-2 and MMP-9 genes. Moreover, they reduced the migratory and invasive abilities of these cells [ 106 ]. In conclusion, in the context of endometriosis, BMSCs, eMSCs, and MenSCs may all promote the development of the disease, and the current focus of research is to block the mechanisms by which they contribute to its progression. ADMSCs have been shown to inhibit endometriosis through immune regulation; however, due to a limited number of studies, the specific regulatory factors involved remain debatable. The role of hUC-MSCs is still unclear, and further experiments are needed to elucidate their involvement in the development of endometriosis. Premature ovarian insufficiency (POI) is defined as ovarian dysfunction that occurs in women before the age of 40 and is characterized by elevated follicle-stimulating hormone (FSH) levels, decreased estrogen levels, and menopausal symptoms, which ultimately result in the loss of fertility [ 107 ]. Diagnostic criteria for POI include a clear history of surgical menopause (removal of both ovaries) or menstrual irregularities such as primary amenorrhea (absence of menstruation), secondary amenorrhea (absence of menstruation for at least 4 months), or hypomenorrhea (irregular or infrequent menstrual periods) [ 107 ]. Additionally, FSH levels > 25 IU/L [ 108 ] or > 30 IU/L [ 109 ] (with at least four to six weeks between tests) are diagnostic of POI. Historically, POI was referred to as premature ovarian failure (POF), though the term POF is considered inaccurate, as patients with POF still have a 5–10% chance of conceiving. Approximately 80% of reported pregnancies in these patients result in healthy births [ 110 ]. Given that some studies still use the term POF, the original formulation (POI/POF) will be used in this paper. MSCs have been widely studied for their potential therapeutic effects on POI, with a particular focus on umbilical cord-derived MSCs. Exosomes derived from MSCs have also been extensively investigated in the context of POI; however, this aspect will not be summarized in this paper. The primary outcomes of these studies generally assess ovarian function recovery, including increases in ovarian size and weight, follicle count, granulosa cell numbers, estradiol (E2) levels, and decreases in FSH levels. Most animal models used in these studies were induced by cyclophosphamide (CTX), while some used zona pellucida sperm-binding protein 3 (ZP3) peptide to induce autoimmune POI. UC-MSCs treatment has been shown to significantly improve ovarian function and restore hormone secretion and follicular development in chemotherapy (CTX)-induced POI. The underlying mechanisms for this effect are primarily related to the reduction of granulosa cell apoptosis and modulation of the immune response. UC-MSCs inhibit granulosa cell apoptosis through the activation of the AKT and P38 signaling pathways, while also down-regulating the expression of pro-inflammatory cytokines, such as IL-6 and IL-1β, and up-regulating the expression of anti-inflammatory cytokines including IL-10, tumor necrosis factor-α stimulated gene-6 (TSG-6), and VEGF. This results in a reduction in polymorphonuclear neutrophil (PMN) and macrophage (Mφ) infiltration in ovarian tissues, ultimately alleviating the inflammatory response [ 111 ]. Yin N et al. demonstrated that heme oxygenase-1 (HO-1) in hUC-MSCs regulates autophagy and up-regulates CD8 + T cell cycling through activation of the c-Jun N-terminal kinase/ B-cell lymphoma 2 (JNK/Bcl-2) signaling pathway, which contributes to restoring ovarian function in POF mice [ 112 ]. Additionally, hUC-MSCs have been found to improve ovarian function and endometrial tolerance in POF mice by modulating the T helper cell type 1/ T helper cell type 2 (Th1/Th2) cytokine balance, decreasing levels of Th1 cytokines (such as IFN-γ and IL-2), and significantly increasing the levels of the Th2 cytokine IL-4. They also influence the expression of uterine natural killer (uNK) cells [ 113 ]. Furthermore, hUC-MSCs act through the nerve growth factor/ tropomyosin receptor kinase A (NGF/TrkA) signaling pathway to reduce granulosa cell apoptosis and promote follicular development [ 114 ]. Beyond mouse and rat models, studies have also been conducted using porcine models of POF. Cai J et al. administered hUC-MSCs to a CTX-induced POF model in Tibetan pigs, and their findings suggested that hUC-MSCs may inhibit apoptosis via regulation of the AKT/ERK1/2 signaling pathway. They also significantly improved ovarian function and structure in these pigs, as well as modulated hormone levels [ 115 ]. In addition, metabolomics studies have explored the mechanisms by which hUC-MSCs restore ovarian function. hUC-MSCs improved ovarian function in CTX-induced POI mice by activating the nuclear-related factor-2 (Nrf-2) antioxidant pathway, enhancing iron metabolism (Nrf-2/ ferritin heavy chain 1(FTH1)), and promoting the antioxidant response (Nrf-2/ glutathione peroxidase 4 (GPX4)), thereby inhibiting ferroptosis [ 116 ]. Furthermore, hUC-MSCs activated the PI3K pathway, which led to increased free amino acid levels, improved lipid metabolism, and reduced monosaccharide concentrations, ultimately restoring ovarian function [ 117 ]. H₂O₂ pretreatment further enhanced the structure and function of damaged ovaries, reducing granulosa cell apoptosis and restoring sex hormone levels (increased E2 levels and decreased FSH levels) by improving the migration ability and survival rate of hUC-MSCs [ 118 ]. In addition to chemotherapy-induced POF, hUC-MSCs have shown therapeutic effects in autoimmune-induced POF rat or mouse models [ 119 ]. The overexpression of miR-21 in UC-MSCs may play a critical role in the restoration of ovarian function in ZP3 peptide-induced autoimmune POI mice, potentially through inhibition of the phosphatase and tensin homolog /Akt/ forkhead box O3a (PTEN/Akt/FOXO3a) signaling pathway. miR-21 also enhanced the therapeutic effects of UC-MSCs by upregulating CD8⁺CD28⁻ T cells and their secretion of the anti-inflammatory cytokine IL-10 [ 120 ]. Fig. 3 Therapeutic mechanisms of UC-MSCs in POI. Umbilical cord mesenchymal stem cells (UC-MSCs) are a promising treatment for premature ovarian insufficiency (POI). They modulate the immune microenvironment by downregulating cytokines (IL-2, IL-6, IL-1β, IFN-γ) and upregulating cytokines (IL-4, IL-10, TSG-6, VEGF). UC-MSCs reduce the number of Th1 cells, neutrophils (PMN), uterine NK cells (uNK cells), and macrophages ( Mφ ), while increasing Th2 cells to restore ovarian immune balance. They also regulate autophagy, protect against oxidative damage by inhibiting ferroptosis, and improve ovarian function through multiple signaling pathways, including PI3K, AKT/ERK1/2, and NGF/TrkA. The schematic diagram is created with BioRender.com (Agreement number: SH28G51OG9) Therapeutic mechanisms of UC-MSCs in POI. Umbilical cord mesenchymal stem cells (UC-MSCs) are a promising treatment for premature ovarian insufficiency (POI). They modulate the immune microenvironment by downregulating cytokines (IL-2, IL-6, IL-1β, IFN-γ) and upregulating cytokines (IL-4, IL-10, TSG-6, VEGF). UC-MSCs reduce the number of Th1 cells, neutrophils (PMN), uterine NK cells (uNK cells), and macrophages ( Mφ ), while increasing Th2 cells to restore ovarian immune balance. They also regulate autophagy, protect against oxidative damage by inhibiting ferroptosis, and improve ovarian function through multiple signaling pathways, including PI3K, AKT/ERK1/2, and NGF/TrkA. The schematic diagram is created with BioRender.com (Agreement number: SH28G51OG9) While umbilical cord MSCs have been the primary focus of research (Fig.  3 ), there are also studies involving other common types of MSCs. Human PMSCs were able to improve ovarian function and follicular development in autoimmune POF mice by inhibiting the overactivation of the inositol-requiring enzyme 1α signaling pathway and reducing granulosa cell apoptosis [ 121 ]. Furthermore, hPMSCs treatment led to an increase in the proportion of Treg cells, a decrease in IFN-γ, and an increase in TGF-β, resulting in the restoration of ovarian function [ 122 ]. BMSCs have also shown potential in enabling the formation or repair of primordial follicles in the ovaries of CTX-induced POF mice, restoring hormonal balance and fertility in the damaged ovaries [ 123 ]. However, some studies have reported that this effect gradually diminished after 78 days post-transplantation [ 124 ]. In addition, hBMSCs treatment was found to be safe, with no tumor formation observed in mice after injection and no detectable integration of human DNA into the offspring genome [ 124 ]. Recently, ADMSCs have been shown to increase the number of healthy follicles in a CTX-induced POI model, improve anti-Müllerian hormone (AMH) levels, and exert an anti-apoptotic effect by regulating the expression of proteins such as Caspase3, Connexin43, and Pannexin1 [ 125 ]. MenSCs have also demonstrated the ability to improve ovarian function in chemotherapy (cisplatin-induced) POF mice by reducing granulosa cell apoptosis and ovarian interstitial fibrosis. Their reparative effects are mainly mediated through the secretion of cytokines and growth factors, such as fibroblast growth factor 2 (FGF2), rather than direct differentiation into oocytes [ 126 ]. However, Liu T et al. suggested that MenSCs could differentiate into cells resembling ovarian granulosa cells when stimulated by the ovarian microenvironment, thereby improving ovarian function in CTX-induced POF mice, increasing ovarian weight, raising plasma E2 levels, and reducing the number of atretic follicles [ 127 ]. In addition to the commonly studied MSCs, some emerging MSCs have shown promising potential for breakthroughs in POI treatment. Human hair follicle-derived MSCs may improve ovarian function in a cyclophosphamide-induced premature ovarian failure mouse model by inhibiting ferroptosis in granulosa cells and modulating the Kelch-like ECH-associated protein 1 (KEAP1)/NRF2/HO-1 pathway. They are considered to be more effective than hUC-MSCs [ 128 ]. Human embryonic stem cell-derived MSCs can also treat CTX-induced POF mice, potentially through paracrine mechanisms that involve the secretion of VEGF, IGF-2, and hepatocyte growth factor which help improve ovarian function, reduce granulosa cell apoptosis, and restore fertility [ 129 ]. CD44⁺/CD105⁺ human amniotic fluid mesenchymal stem cells proliferate rapidly in vitro and can survive and proliferate for extended periods in the ovaries of a POF mouse model, suggesting they may also be a promising therapeutic option for POF [ 130 ]. Polycystic ovary syndrome (PCOS) is a disorder characterized by hyperandrogenism, insulin resistance, ovulatory dysfunction, and polycystic ovarian morphology [ 131 ], with a reported prevalence ranging from 3 to 15% of women of childbearing age [ 132 ]. The anti-inflammatory, antioxidant, and immunomodulatory properties of MSCs have shown promise in ameliorating PCOS, primarily through the secretion of bioactive factors or by direct cell-to-cell interactions. Among these, ADMSCs and BMSCs have been the most extensively studied. In rat models of PCOS, ADMSCs were found to significantly improve ovarian function and metabolic status by regulating mitochondrial dynamics, enhancing mitochondrial function, and reducing oxidative stress and inflammatory responses via the PI3K/AKT signaling pathway [ 133 ]. Additionally, human ADMSCs significantly enhanced ovarian function and follicular development in PCOS rats by modulating epigenetic modifications, such as DNA methylation and histone deacetylation, and increasing estrogen receptor expression [ 134 ]. Chugh RM et al. reported that hBMSC treatment significantly improved metabolic phenotypes restored normal ovarian function, and increased fertility in PCOS mice. The inflammation-modulatory effects of hBMSC treatment included a significant increase in the gene expression of IL-10 and its receptor in ovarian tissues, elevated serum levels of IL-10, IFN-γ, and tissue inhibitor of metalloproteinase-2, and a decrease in the gene expression of pro-inflammatory markers such as IL-6, IL-1β, CCL2, and CD11c in the adipose tissue of PCOS mice [ 135 ]. Their further investigation revealed that hBMSC treatment restored normal ovarian function and gene expression, potentially through the inhibition of H295R cell proliferation and androgen secretion via the upregulation of bone morphogenetic protein-2 and the reduction of inflammatory marker expression [ 136 ]. In vitro experiments on PMSCs have shown that these cells may restore folliculogenesis, repair ovarian function, correct hormonal imbalances, and improve lipid profiles and liver function in a PCOS rat model. These effects were mediated through the secretion of various biologically active mediators, such as growth factors and anti-apoptotic cytokines, modulation of intra-ovarian signaling pathways, promotion of angiogenesis, and improvement in blood perfusion to damaged ovarian tissues [ 137 ]. However, this study did not directly confirm whether PMSCs migrated to the ovaries. In addition to studies on cell therapy using MSCs, research on MSC-derived exosomes for the treatment of PCOS has been extensive but will not be discussed in detail here [ 138 , 139 ]. Pelvic floor dysfunction (PFD) occurs when the supportive tissues of the female pelvic floor become weakened due to degeneration and trauma. It encompasses a range of disorders, including pelvic organ prolapse (POP), stress urinary incontinence (SUI), and genital fistulae [ 140 ]. MSC transplantation has shown promise in repairing weakened pelvic floor tissues and improving biomechanical properties by promoting extracellular matrix growth, neoangiogenesis, and smooth muscle formation. Additionally, MSCs in combination with biomaterials for the treatment of POP are actively being researched [ 141 ]. In a study using an aged rat model with a total vaginal incision, Ben Menachem-Zidon O et al. found that BMSCs significantly improved the inflammatory response in aged rats. This was evidenced by a reduction in the number of CD68 + macrophages and a decrease in the co-expression of the pro-inflammatory cytokine TNF-α [ 142 ]. Moreover, BMSCs promoted angiogenesis and modulated the expression of MMP9, which significantly improved the healing and biomechanical properties of vaginal tissues [ 143 ]. Similarly, in a mouse model of PFD induced by vaginal dilation, Hu L et al. observed that exosomes derived from mouse BMSCs significantly reduced inflammatory cytokines (IL-6, IL-1β, TNF-α) and decreased tissue damage and neutrophil infiltration. These findings demonstrated the anti-inflammatory, tissue regeneration-promoting, and pelvic support function-improving effects of BMSCs [ 144 ]. Furthermore, hBMSCs have been shown to enhance tissue repair and regeneration of damaged urethra, which holds promise for the treatment of SUI [ 145 ]. Although BMSCs combined with calcium alginate composite gel injection therapy [ 146 ]and tissue-engineered slings incorporating BMSCs with biodegradable silk fabric scaffolds [ 147 ] have shown potential in treating SUI, their clinical applications have yet to be validated. Zhu L’s team explored the potential of hUC-MSC transplantation in repairing vaginal tissue damage in a de-ovulated rhesus monkey model. They found that hUC-MSCs significantly up-regulated the expression of smooth muscle, collagen I, elastin, and fibrillin-5 while down-regulating the expression of MMP2, MMP9, and MMP13 [ 148 ]. This suggests that hUC-MSCs may promote collagen and smooth muscle production in the vaginal wall through paracrine actions [ 149 ]. Further investigation into the use of hUC-MSC-based bioengineered scaffolds in repairing vaginal tissues was conducted in an ovariectomized rhesus monkey model. The implantation of hUC-MSCs on small intestinal submucosa grafts effectively promoted the repair and regeneration of vaginal tissues and significantly improved the biomechanical properties of the damaged vaginal tissues [ 150 ]. Recently, the vagina-implantable electro-stimulated stem cell mesh (VECM) developed by Xiao A et al. has shown promising results in the treatment of POP. The study demonstrated that electrical stimulation of the VECM significantly promoted the proliferation and migration of hUC-MSCs, enhancing the repair and regeneration of pelvic floor muscles. The VECM also exhibited a good safety profile and biodegradability, offering a safer alternative to the risks associated with traditional surgical removal of implants [ 151 ]. In another study, ADMSCs were obtained from young female rats and applied to a rat anterior vaginal wall nerve injury model induced by bilateral pubic neurotomy. The results showed that ADMSCs significantly increased the nerve content of the anterior vaginal wall. Additionally, gene expression analysis related to nerve regeneration revealed that the group treated with ADMSCs on gelatin scaffolds exhibited higher and earlier expression of nerve-related marker genes at the early stages of treatment [ 152 ]. Wu X et al. developed a tissue-engineered mesh based on ADMSCs for POP treatment. The mesh was designed to continuously release basic FGF, which enhanced tissue repair. In both in vitro and in vivo experiments, the mesh demonstrated excellent biocompatibility and tissue regeneration properties [ 153 ]. Furthermore, studies have shown that scaffolds seeded with eMSCs improved tissue repair, enhanced biomechanical properties, and reduced foreign body reactions in immunodeficient POP rats. This combination of eMSCs and novel gelatin-coated polyamide scaffolds provided significant therapeutic benefits, although this model does have limitations in fully mimicking the physiological environment of human POP repair [ 154 ]. With their strong regenerative capabilities, MSCs combined with novel scaffold materials hold great promise for the treatment of pelvic floor dysfunction. This innovative therapy not only significantly reduces surgical trauma but also enables long-lasting cellular repair and tissue regeneration through the slow-release properties of the scaffold. This approach offers a safer and more effective long-term treatment option for patients suffering from pelvic floor disorders. Gynecological malignant tumors, including ovarian cancer, endometrial cancer (EC), and cervical cancer, pose significant health risks for women. Traditional treatment options, such as surgery, chemotherapy, and radiotherapy, have reached a therapeutic bottleneck, prompting the exploration of novel approaches such as immunotherapy and cell therapy [ 155 – 157 ]. MSCs, along with their exosomes, have shown promise not only in tumor inhibition or promotion but also in reversing chemotherapy-induced ovarian dysfunction. Detailed mechanisms of MSCs in improving chemotherapy-induced ovarian impairment are discussed in Sect. 3.3. In ovarian cancer, the mechanisms of MSC therapy are complex and present contradictory findings. For example, Chu Y et al. used both in vitro and in vivo models to demonstrate that ADMSCs may promote the proliferation and invasion of epithelial ovarian cancer cells by upregulating MMPs [ 158 ]. However, other studies have suggested a different effect, with human amniotic fluid-derived MSCs inhibiting SKOV3 ovarian cancer cell proliferation and inducing apoptosis. This effect was associated with the upregulation of P53 and P21 and the downregulation of CyclinD1 and CyclinB1 [ 159 ]. Similarly, Szyposzynska A et al. proposed that the exocytosis of ADMSC-derived bodies might inhibit ovarian cancer [ 160 ], though other studies have reported a tumor-promoting effect of ADMSCs [ 158 , 161 ]. Some studies have explored the use of MSCs as vectors for targeted ovarian cancer treatment. Shi S et al. demonstrated the potential of using BMSCs as vectors to deliver lentivirus-mediated E4-NIS genes to ovarian cancer cells [ 162 ]. Another innovative approach by Mader EK et al. involved using ADMSCs as a vector to protect a lysogenic measles virus (MV) from neutralization by anti-measles antibodies. The MSCs facilitated the delivery of the virus to ovarian cancer cells, allowing the MV to kill tumor cells [ 163 ]. This therapy has entered clinical trials (ClinicalTrials.gov number: NCT02068794 ) . Although results have not yet been published, the potential effects are promising. MSCs have been less extensively studied in the context of EC and cervical cancer. However, there have been promising findings in these areas. For example, it has been reported that eMSCs inhibit the Wnt/β-catenin signaling pathway by secreting dickkopf-1-related proteins, which in turn suppresses the proliferation and stemness of EC cells. This effect is more pronounced than that observed with ADMSCs or UC-MSCs. Furthermore, the inhibitory impact of eMSCs combined with progesterone appears to be superior to progesterone treatment alone in EC cells, which may offer a potential fertility-preserving therapeutic strategy for young EC patients [ 164 ]. Li X et al. also found that exosomes derived from hUC-MSCs could efficiently deliver miR-302a into EC cells. miR-302a was shown to inhibit tumor cell proliferation and migration by downregulating cyclin D1 and inhibiting the AKT signaling pathway [ 165 ]. Additionally, several studies have suggested that exosomes from BMSCs and Wharton’s Jelly MSCs could inhibit the progression of cervical cancer [ 166 – 168 ].

MSCs are primarily sourced from two categories: adult sources and perinatal sources. Adult MSCs can be isolated from specific tissues, including bone marrow, adipose tissue, endometrium, peripheral blood, menstrual blood, dental pulp, and muscle. Perinatal mesenchymal stem cells are derived from the umbilical cord (including cord blood), placenta (such as the amnion, chorionic frondosum, and basal decidua), fetal membranes, and amniotic fluid [ 19 ]. In gynecology, MSCs are commonly sourced from bone marrow, adipose tissue, menstrual blood, endometrium, umbilical cord, umbilical cord blood, and placenta. Each source has unique characteristics, collectively forming a ‘cellular treasure trove’ for gynecological applications. MSCs from the umbilical cord, umbilical cord blood, placenta, and menstrual blood are particularly rich in MSCs. Gynecologists have transformed these once-regarded waste materials into valuable resources, injecting new momentum into regenerative medicine research and offering fresh perspectives and hope for treating many gynecological diseases. Bone marrow mesenchymal stem cells (BMSCs) are the most established and widely used MSCs. BMSCs must be obtained through invasive methods, and their number in the bone marrow is limited (approximately 0.01 − 0.001%). Typically, BMSCs need to be expanded and cultured to obtain an adequate number of cells for treatment [ 22 ]. Autologous BMSCs do not trigger immune-related rejection, unlike allogeneic BMSCs, which may cause immune system-related complications [ 23 ]. Additionally, the quality of allogeneic BMSCs is influenced by the donor’s age and overall health [ 24 ]. In August 2022, the British Standards Institution (BSI) published the international standard ISO/TS 24651:2022 for BMSCs. This standard outlines the requirements for the collection, isolation, culture, characterization, quality control, cryopreservation, storage, thawing, distribution, and transport of human bone marrow mesenchymal stem cells (hBMSCs) for research purposes [ 25 ]. Adipose-derived mesenchymal stem cells (ADMSCs) are increasingly used due to their abundant availability, with up to 1 billion cells potentially generated from 300 g of adipose tissue through liposuction [ 26 ]. Compared to bone marrow MSCs, harvesting ADMSCs is less invasive, offers a faster rate of cell proliferation, and is primarily performed on adipose tissue from the abdomen and thighs [ 27 , 28 ]. Additionally, ADMSCs offer distinct advantages in bone regeneration and skin healing [ 29 , 30 ]. First reported in 2007 [ 31 ], menstrual blood stem cells (MenSCs) express classical MSC markers, including CD29, CD73, CD90, and CD105, but lack expression of CD19, CD34, CD45, and HLA-DR [ 32 , 33 ]. MenSCs have the advantage of being relatively easy to individualize and collect, in addition to exhibiting the general characteristics of MSCs [ 34 ]. Under optimal culture conditions, MenSCs from young, healthy women can double their proliferation every 20 h, which is twice the rate observed in bone marrow MSCs. This high proliferation rate results in increased expression of embryonic trophic factors and the extracellular matrix in MenSCs [ 35 ]. As a relatively new addition to stem cell therapy, MenSCs require further exploration for a broader range of applications, as no clinical trials have been conducted to date. Endometrial mesenchymal stem cells (eMSCs), derived from the female endometrium, share similarities with MenSCs. eMSCs exhibit strong self-renewal capacity and multidirectional differentiation potential, contributing to the repair of the functional layer of the endometrium during the normal menstrual cycle. However, due to the challenges in collection, their clinical application potential is not as promising as that of MenSCs. eMSCs have shown potential for repairing endometrial damage in animal models [ 36 ]. However, human-derived eMSCs struggle to survive long-term in animals, limiting further research. The umbilical cord contains a high concentration of MSCs, which are typically isolated from Wharton’s jelly. In the umbilical cord, the highest concentration of MSCs and the highest derivation rate are isolated from Wharton’s jelly [ 37 , 38 ]. Compared to BMSCs, umbilical cord mesenchymal stem cells (UC-MSCs) exhibit significantly higher proliferative and migratory capacities. Additionally, UC-MSCs are produced in greater quantities, meeting a broader range of research and application needs. They are characterized by high safety, low immunogenicity, high purity, and low application risk [ 39 ]. In August 2022, the BSI published an international technical specification (ISO/TS 22859-1:2022) for human umbilical cord mesenchymal stem cells (hUC-MSCs) derived from umbilical cord tissue [ 40 ]. In addition to being enriched with MSCs, umbilical cord blood also contains MSCs, alongside the well-known hematopoietic stem cells [ 41 ]. Compared to adult-derived MSCs, umbilical cord blood mesenchymal stem cells (UCB-MSCs) exhibit higher cell proliferation and clonogenic rates, with significantly lower expression of senescence markers such as p53, p21, and p16 [ 42 ]. This suggests that UCB-MSCs have notable biological advantages, including shorter culture time, greater large-scale expansion capacity, delayed cellular senescence, and enhanced anti-inflammatory function. The placenta is a critical organ for material exchange between the fetus and the mother. Its structure primarily consists of the amnion, chorionic frondosum, and basal decidua, all of which are enriched with MSCs. Placenta mesenchymal stem cells (PMSCs) may have superior proliferative capacity compared to umbilical cord MSCs [ 43 ], and exhibit more pronounced immunosuppressive effects on dendritic cells and T cells. However, the complex composition of the placenta makes it challenging to isolate pure and safe MSCs. Additionally, MSCs from different tissue sources exhibit tissue-specific characteristics, and individual donor variations further complicate their use [ 44 ]. The amnion is the innermost layer of the fetal membrane, directly in contact with both the amniotic fluid and the fetus. It consists of an epithelial layer, a basement membrane, and a mesenchymal layer. The amnion is a key component of the placenta, and its MSCs have become a focus of current research due to their potential in tissue repair and anti-inflammatory effects [ 45 ]. Additionally, amniotic epithelial cells also possess stem cell properties. Full-term amniotic epithelial cells predominantly express epithelial cell markers (e.g., CD324, CK18, CD9) and partially express embryonic stem cell markers (e.g., SSEA-3/4, TRA1-60), but do not express mesenchymal markers (e.g., CD90, CD105, Vimentin) [ 46 ]. These cells also hold the potential for treating gynecological diseases. To achieve large-scale production and quality control of stem cells and their exosomes, researchers have begun to employ advanced techniques in the hope of obtaining more stable cell lines. In 1973, Reznikoff and colleagues isolated the C3H10T1/2 cell line [ 47 ]. The C3H10T1/2 cell line is a mouse embryonic-derived mesenchymal stem cell line known for its multi-lineage differentiation potential, offering unique advantages in adipogenic and osteogenic differentiation [ 48 , 49 ], and has also been reported to form cells with neuron-like morphology [ 50 ]. Additionally, Gao et al. derived the OP9 cell line from mouse bone marrow and found it to share the same immunophenotype and multi-lineage differentiation potential as typical MSCs [ 51 ]. Other mouse/rat BMSC-derived cell lines include the BMC-9 [ 52 ], FMS/PA6-P [ 53 ], Kusa-A1 [ 54 ], and rBM25/S3 [ 55 ]lines. Chen et al. constructed an immortalized mesenchymal stem cell line, hTERT-UCMSC, by lentiviral transduction of hUC-MSC. The exosome production and characteristics of the immortalized hTERT-UCMSCs remained consistent with the primary cells up to the 35th generation, suggesting their potential for the treatment of liver failure [ 56 ]. Additionally, UE7T-13 cells, derived from BMSCs, have been extensively studied for their liver-related applications [ 57 , 58 ]. Nagai et al. isolated the B10 cell line by transfecting primary fetal BMSCs and discovered that, in a mouse intracerebral hemorrhage stroke model, transplanted B10 cells could integrate into the host brain, survive, and differentiate into neurons and astrocytes, also improving the behavior of intracerebral hemorrhage animals [ 59 ]. Despite the existence of these various cell lines, the most commonly used in gynecological disease research remains MSCs directly isolated from humans or mice/rats. Furthermore, developing an immortalized MSC line suitable for gynecological disease research represents a significant direction for future studies. Such a cell line would aid scientists in gaining a deeper understanding of the pathophysiology of gynecological diseases and provide a robust tool for the development of novel therapeutic approaches.

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