Oxygen self-supplied upconversion nanoplatform loading cerium oxide for amplified photodynamic therapy of hypoxic tumors

Photodynamic therapy (PDT) has been widely used in preclinical trials for treating various tumors. However, the hypoxic environment of tumors and the limited penetration depth of ultraviolet light severely weaken the PDT effect. To solve the above problems, a near-infrared (NIR) light-triggered oxygen (O2) self-supplied phototherapeutic platform (UCNPs/CeO2/Ce6/BSA) for amplified PDT performance against solid tumors by alleviating tumor hypoxia has been rationally developed. The platform has excellent stability and can continuously decompose H2O2 for sustained O2 supply to synergize 1O2 generation, thus inducing an enhanced mortality rate (59%) of ID8 cells in vitro under hypoxic + H2O2 conditions. The growth of solid tumors was effectively inhibited and the mouse survival rate was dramatically enhanced via a superior PDT therapeutic performance. This reported study facilitated the positive development of multifunctional diagnosis and treatment platforms under long-wavelength excitation for O2 self-supplied tumor treatments.