Polymer-coated calcium peroxide nanoparticles as an oxygen self-supplying platform for enhanced photodynamic therapy

Photodynamic therapy, employing photosensitizer catalysis to convert oxygen into cytotoxic reactive species upon light irradiation, holds high promise in tumor therapy due to its high selectivity and non-invasiveness. However, the anticancer efficacy is greatly limited by the hypoxia microenvironment of tumor tissue. Herein, we report an oxygen self-supplying nano-platform for photodynamic therapy, which is fabricated by calcium peroxide nanoparticles with surface modification of a copolymer, PMPS- b -P(NIPAAm- co -VBRB) by silanization. In this system, calcium peroxide nanoparticle acts as an oxygen donor while PMPS- b -P(NIPAAm- co -VBRB) plays the role of photosensitizer and can stabilize shell of calcium peroxide nanoparticles. The resultant polymer-coated nanoparticles have a uniform size of 228 nm measured by dynamic light scattering. The polymer-coated calcium peroxide nanoparticles show greater production efficiency of singlet oxygen to deplete 1,3-diphenylisobenzofuran than PMPS- b -P(NIPAAm- co -VBRB) upon the exposure to the [email protected]  nm. The result demonstrates that the polymer-coated calcium peroxide nanoparticles are effective for oxygen generation and hold potential to enhance the efficacy of photodynamic therapy.