Noninvasive Needle‐Free Cancer Vaccine Cream Patch Based on Fluorinated Chitosan

Abstract In recent years, cancer vaccines that intend to specifically initiate host immune responses against cancer have achieved some clinical success. Delivery of vaccines with traditional needles is usually associated with the risk of infection and poor patient compliance. The development of needle‐free vaccines may overcome these limitations. In this work, a needle‐free patch is designed for effective cancer vaccination using a fluorine chain‐modified cationic polymer, fluorinated chitosan (FCS), which is able to transdermatically deliver the antigen to antigen‐presenting cells in the skin. Specifically, a transdermal carrier, FCS, and model antigen ovalbumin (OVA) can self‐assemble into nanoparticles, which can reversibly open the tight junction‐associated proteins of epithelial cells and penetrate across the epidermis. The needle‐free cancer vaccine patch is fabricated by mixing FCS‐OVA nanoparticles with the US Food and Drug Administration‐approved immune adjuvant imiquimod (R837) in blank cream. Such a needle‐free cancer vaccine can generate robust immune responses to protect mice against ovalbumin‐expressing melanoma (B16‐OVA). Compared to traditional intradermal injection, needle‐free cancer vaccines achieved an even more efficient protection effect against B16‐OVA cancer cells. This work indicated that the novel needle‐free cancer vaccine may provide a compelling technology for simple and safe vaccination, which may help to increase vaccination coverage.