Polymeric Drug Delivery Materials for Cancer Immunotherapy

In recent years, immunotherapy, as a new therapeutic method, received extensive attention in the field of tumor therapy due to the exciting therapeutic effects on many types of malignant tumors. Though the development of immunotherapy is in full swing, immunotherapy still faces many challenges, such as low immune response rate, immune related adverse events. Using drug delivery materials for targeted delivery immune agents is an effective means to solve the current problems of immunodrugs and further improve the therapeutic index. Compared to chemotherapeutic agents, the target, mechanism and mode of action of immune agents are different, which poses a new challenge to the design of drug delivery materials. In this paper, we summarized the challenges in the process of immunodrugs delivery, and introduced the design ideas and representative results of polymeric materials for immune drug delivery to the tumor and lymph nodes. For the delivery of immune drug to tumor, we firstly showed 3 types of nanoparticles-polypeptide-dexamethasone conjugate, aspirin polymeric prodrug and nano-assembly of bile acid receptor modulators for releasing the immunosuppression in the tumor site. Then we introduced the poly(lactic acid) block polyethyleneimine CpG loaded nanoparticles combination with oxaliplatin for inducing the immunogenic death and further enhancing the in situ antitumor immunity. Finally, we present the strategy of hierarchical delivery of immune agents to tumors and lymph nodes using supramolecular assembled programmable nanomedicine. Furthermore, the influence of drug release mode on the immune stimulation effect was explored by the implants crosslinked by poly(ethylene glycol) and polysaccharide. For the delivery of immune drug to lymph node, pathogen-mimicking polymeric nanoparticles were used for realizing the efficient reflux of antigen and adjuvant to lymph nodes, and polyethyleneimine derivatives with stimulator of interferon genes (STING) adjuvant function were synthesized for achieving the spatiotemporal synergy between activating antigen presenting cells and promoting antigen cross presentation. Finally, we forwarded the problems that need to be solved and the future research direction in the field of immunodrug delivery.