Figure 1.

Schematic illustration of PEI‐based nanovaccine. PEI was sequentially modified with PEG and neoantigens via amide and disulfide bond, respectively. Then, polycationic PEI conjugates were self‐assembled with polyanionic CpG adjuvants through electrostatic interaction to form neoantigen nanovaccine. Diverse types of antigens and adjuvants can be incorporated into the complex allowing flexible and modular design for personalized cancer vaccines. The nanovaccine can increase the cellular uptake of neoantigens and adjuvants by APCs and promote activation and antigen cross‐presentation to effectively cross‐prime antigen‐specific T cells for robust antitumor immunity and antitumor efficacy.