Oxygen self-supplied nanoparticle for enhanced chemiexcited photodynamic therapy.

Photodynamic therapy (PDT) is one of the most promising strategies for efficiently curing cancer. However, it still faces severe challenges including poor laser penetration and the insufficient oxygen (O2) in solid tumors. Here, we constructed an intelligent O2 self-supplied nanoparticles (NPs) for tumor hypoxia relief as well as effective chemiexcited photodynamic therapy. The NPs were obtained via self-assembly of bovine serum albumin (BSA), bis[3,4,6-trichloro2-(pentyloxycarbonyl)phenyl]oxalate (TCPO), perfluorohexane (PFH), and chlorin e6 (Ce6) (denoted as BTPC). In the H2O2-overexpressed tumor cells, the TCPO in the NPs could react with H2O2, thus releasing energy to activate photosensitizer Ce6 to generate cytotoxic singlet oxygen (1O2) to kill tumor cells in a laser irradiation-independent manner. Moreover, the O2 carried by PFH could not only reduce therapeutic resistance by alleviating tumor hypoxia but also increase 1O2 generation for enhanced chemiexcited photodynamic therapy. The remarkable cytotoxicity to various cancer cell lines and A549 tumor manifested the advantage of BTPC in alleviating hypoxic status and inhibiting tumor growth. Our results proved that BTPC appeared to be a promising therapeutic nanoplatform for cancer therapy.