Antigen-Directed Fabrication of a Multifunctional Nanovaccine with Ultrahigh Antigen Loading Efficiency for Tumor Photothermal-Immunotherapy

Current antigen-encapsulated multifunctional nanovaccines for oncotherapy suffer from limited antigen loading efficiency, low yield, tedious manufacture, and systemic toxicity. Here, an antigen-directed strategy for the fabrication of multifunctional nanovaccine with ultrahigh antigen loading efficiency in a facile way for tumor photothermal-immunotherapy is shown. As a proof of concept, a model antigen ovalbumin (OVA) is used as a natural carrier to load a representative theranostic agent indocyanine green (ICG). Mixing OVA and ICG in aqueous solution gives the simplest multifunctional nanovaccine so far. The nanovaccine owns antigen loading efficiency of 80.8%, high yield of >90%, intense near-infrared absorption and fluorescence, excellent reproducibility, good aqueous solubility and stability, and favorable biocompatibility. These merits not only guarantee sensitive labeling/tracking and efficient stimulation of dendritic cells, but also reliable imaging-guided photothermal-immunotherapy of tumors and tumor prevention. The proposed strategy provides a facile and robust method for large-scale and reproducible fabrication of multifunctional nanovaccines with ultrahigh antigen loading efficiency for tumor therapy.