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 introduce 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 polylactic 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 polyethylene 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.