Tumor Antigen-Coated Two-Dimensional Black Phosphorus as a Nanovaccine for Synergistic Cancer Photothermal Therapy and Immunotherapy

Vaccine immunotherapy is paving the way for an effective long-term immune response and targeted destruction of tumor cells and shows promise as a leading strategy in tumor treatment. Nanoparticles are crucial in combining vaccine immunotherapy and photothermal therapy (PTT), generating local tumor thermal ablation, and triggering a powerful antitumor immune response that inhibits tumor recurrence. In this study, we designed a nanovaccine that combined PTT and immunotherapy for tumors using two-dimensional black phosphorus (BP) as a nanoplatform that was modified with maleimide poly(ethylene glycol) (PEG-MAL) and coated with tumor antigen proteins (BP-PEG-MAL@antigen). The BP-PEG-MAL@antigen nanovaccines displayed outstanding stability and biocompatibility due to the comodification of PEG and antigen proteins. The nanovaccines induced strong immune responses in vitro and in vivo that effectively inhibited orthotopic and bilateral tumor growth, prolonged survival time, and improved the survival rate of mice. In addition, the nanovaccines generated a long-term immune response and effectively inhibited tumor recurrence.