Albumin‐Hitchhiking Drug Delivery to Tumor‐Draining Lymph Nodes Precisely Boosts Tumor‐Specific Immunity through Autophagy Modulation of Immune Cells

Tumor-draining lymph nodes (TDLNs) are the first sites where tumor components reach and dendritic cells (DCs) present tumor-associated antigens to T cells. DCs rely on autophagy to process tumor antigens into epitope peptides to form epitope-MHC complexes. Selective delivery of autophagy-stimulating drugs to TDLNs may be a precise strategy to boost chemotherapy-induced antitumor immunity. Here, a multistage stimulating strategy is proposed to activate the antitumor immunity cascade by inducing immunogenic death of tumor cells and elevating antigen presentation of DCs in TDLNs. A tumor-microenvironment-responsive "albumin-hitchhiking" micelle is established by self-assembling tumor-targeting oxaliplatin prodrug and lipophilized trehalose prodrug. This demonstrates that lipophilic modification of trehalose with a DSPE tail and the precise exposure in the tumor site enhances its binding to endogenous albumin and realizes TDLNs-selective reflux, where it upregulates antigen processing and presentation of DCs. This study introduces an approach for targeted delivery to TDLNs and provides insights into mechanisms of autophagy in tumor-specific immunity.