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

Abstract

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.