Construction of Transcutaneous Immuno-oncology Vaccine Patches Based on Total RNA from Immunogenic Cell Death-Induced Tumor Cells: Characterization, Immunological Activity, and Safety Evaluation

In this study, we developed a transdermal tumor vaccine based on total RNA from melanoma cells undergoing immunogenic cell death (ICD). The vaccine employed mannosylated chitosan (MC) modified ethosomes (Eth MC ) as the delivery vehicle, in which the total RNA isolated from tumor cells undergoing celastrol-induced ICD (C-RNA) was electrostatically complexed with protamine (C-RNA-Prt) and subsequently encapsulated. Using electrospray deposition, the C-RNA-Prt loaded Eth MC (C-RNA-Prt@Eth MC ) was immobilized onto a silk fibroin membrane (SFM) to generate a tumor vaccine patch (C-RNA-Prt@Eth MC /SFM). In vitro studies demonstrated that this vaccine effectively targeted and activated dendritic cells (DCs), triggering the secretion of key pro-inflammatory cytokines such as TNF-α, IL-6, and IFN-γ, and promoting T-cell proliferation and differentiation. Animal immunization experiments further confirmed that the vaccine markedly elevated serum levels of pro-inflammatory cytokines, enhanced splenocyte-mediated cytotoxicity against melanoma cells, and exhibited no observable toxicity in major organs. Collectively, this transdermal vaccine patch demonstrated significant immunostimulatory activity, favorable biosafety, and therapeutic potential, providing an effective strategy for the design of personalized transdermal tumor vaccines.