Near infrared light activation of an injectable whole-cell cancer vaccine for cancer immunoprophylaxis and immunotherapy.

Cancer vaccines play a key role in the prevention and treatment of early and recurrent tumors. Although they have been widely studied during the past few decades, designing an efficient and economical cancer vaccine is still challenging. Here, we propose an injectable live cell cancer vaccine (InLCCV) using live tumor cells as immunogenic sources for cancer immunoprophylaxis and immunotherapy. InLCCV is fabricated by loading live mouse breast cancer cells (4T1 cells), gold nanorods (GNRs), and super-low-dose lipopolysaccharide (LPS) into a biocompatible Pluronic F127 in situ hydrogel matrix. After in situ inactivation by the photothermal effect of GNRs upon near-infrared (NIR) laser irradiation, immunogenic cell death (ICD) of 4T1 cells is induced and tumor-associated antigens (TAAs) together with loaded LPS are released subsequently. Therefore, dendritic cells and macrophages are activated accordingly, further stimulating the systemic anti-tumor immune response. After vaccinating with InLCCV, the tumor-free percentage of the mice is 60% and the survival rate during the observation period reaches up to 80%. For lung metastasis, the metastatic foci are 3.9-fold less than those of the control group. The as-developed InLCCV shows much promise as a potential platform for breast cancer immunoprophylaxis and immunotherapy.