Mitochondria-targeted carbon monoxide delivery combined with singlet oxygen production from a single nanoplatform under 808 nm light irradiation for synergistic anticancer therapy

Abstract

A multifunctional nanoplatform (1), MnCO@TPP@C–TiO₂, which consists of a carrier of carbon-doped TiO₂ nanoparticles with surface covalent functionalization of manganese carbonyls and a directing group of triphenylphosphine, was prepared for mitochondria-targeted carbon monoxide (CO) delivery combined with photodynamic therapy (PDT). MnCO@TPP@C–TiO₂ selectively localized in the mitochondria of HeLa cells where the overexpressed-H₂O₂ triggered CO release resulting in mitochondrial damage. And singlet oxygen species generated upon 808 nm near infrared light irradiation further destroyed the mitochondria and induced cancer cells apoptosis. Cytotoxicity assays revealed that the nanoplatform with mitochondria-targeted CO delivery and PDT exhibited the highest lethality against cancer cells in comparison with all the other control samples tested, and it showed good dark biocompatibility with normal cells that express low H₂O₂ levels. This work may provide new insights into combining CO-based gas therapy with traditional PDT for efficient cancer treatment.