Red blood cell-derived nanoerythrosome for antigen delivery with enhanced cancer immunotherapy.

Erythrocytes or red blood cells (RBCs) represent a promising cell-mediated drug delivery platform due to their inherent biocompatibility. Here, we developed an antigen delivery system based on the nanoerythrosomes derived from RBCs, inspired by the splenic antigen-presenting cell targeting capacity of senescent RBCs. Tumor antigens were loaded onto the nanoerythrosomes by fusing tumor cell membrane-associated antigens with nanoerythrosomes. This tumor antigen-loaded nanoerythrosomes (nano-Ag@erythrosome) elicited antigen responses in vivo and, in combination with the anti-programmed death ligand 1 (PD-L1) blockade, inhibited the tumor growth in B16F10 and 4T1 tumor models. We also generated a tumor model showing that "personalized nano-Ag@erythrosomes" could be achieved by fusing RBCs and surgically removed tumors, which effectively reduced tumor recurrence and metastasis after surgery.