Facile Preparation of Metal-Phenolic Networks-Based Lymph Node Targeting Nanovaccine for Antitumor Immunotherapy

Cancer vaccines are being explored for enhanced cancer immunotherapy and prophylaxis. Some of their prevailing weaknesses, however, such as complicated preparation, poor biocompatibility, and failure to elicit strong cellular immune responses, have limited their further clinical applications. Here, we developed a multifunctional nanovaccine that was prepared in a quick and simple way. During the self-assembly of metal-phenolic networks (MPNs), the antigen ovalbumin (OVA) and immunoreactive chlorogenic acid (CHA) were simultaneously loaded. Owing to its dual pH and reduction sensitivities, this nanovaccine could deliver antigens into the cytoplasm of dendritic cells (DCs) and promote the antigen cross-presentation. Moreover, results of in vivo immunization experiments demonstrated that the nanovaccine significantly excited DCs and provoked a robust cellular immune response with restrained activation of regulatory T cells (Tregs), by targeting lymph nodes and CHA functioning. In vivo antitumor assays indicated that the nanovaccine with excellent biosafety afforded great cancer treatment and prevention effects. Overall, the developed nanovaccine based on MPNs shows promise in enhanced cancer immunotherapy by lymph node targeted delivery.