Neutrophils Mediated Multistage Nanoparticle Delivery for Prompting Tumor Photothermal Therapy

Background: Neutrophil-based drug delivery system possesses excellent advantages in targeting at tumour because neutrophils are easily recruited by chemotactic factor in tumor microenvironment. Herein, we developed a novel tactic of multistage neutrophils-based nanoparticle delivery system for promoting photothermal therapy (PTT) of lung cancer. Results: Au nanorod (AuNR) was successfully modified with bovine serum albumin (AuNRB) and further conjugated with RGD (AuNRBR), followed by neutrophil internalisation to obtain neutrophils-based delivery system (AuNRBR/N). The engineered neutrophils efficiently migrated across the epithelial cells due to inflammatory signal. They exhibited better toxicity against Lewis cells with laser irradiation in vitro . Moreover, AuNRBR/N showed significantly more targetability to tumour tissue compared with cell carrier-free AuNRBR, as demonstrated in Lewis tumour-bearing mice. The enhanced tumour homing efficiency of AuNRBR/N together with subsequently released AuNRBR from the neutrophils was favourable for further deep tissue diffusion and contributed to the inhibition of the tumour growth in PTT and improved survival rate (over 120 days). Conclusions: Overall results illustrated that the design of cell-based nanoparticle delivery system for PTT of cancer is promising.