Injectable Anti-inflammatory Nanofiber Hydrogel to Achieve Systemic Immunotherapy Post Local Administration.

Despite the great promise achieved by immune checkpoint blockade (ICB) therapy in harnessing the immune system to combat different tumors, limitations such as low objective response rates and adverse effects remain to be resolved. Here, an anti-inflammatory nanofiber hydrogel self-assembled by steroid drugs is developed for local delivery of antiprogrammed cell death protein ligand 1 (αPDL1). Interestingly, on the one hand this carrier-free system based on steroid drugs can reprogram the pro-tumoral immunosuppressive tumor microenvironment (TME) to antitumoral TME; on the other hand, it would serve as a reservoir for sustained release of αPDL1 so as to synergistically boost the immune system. By local injection of such αPDL1-loaded hydrogel, effective therapeutic effects were observed in inhibiting both local tumors and abscopal tumors without any treatment. This work presents a unique hydrogel-based delivery system using clinically approved drugs, showing promise in improving the objective response rate of ICB therapy and minimizing its systemic toxicity.