Photodynamic therapy (PDT) has shown good therapeutic results in recent years, but the efficacy is limited by the hypoxic environment within cancer cells. At present, most of the research studies on overcoming PDT hypoxia focus on providing exogenous oxygen, but the effect is not outstanding. This work shows an unconventional source of free radicals, compared with the traditional PDT strategy of generating reactive oxygen species, using a radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), ABVN) to generate alkyl radicals, which is free from the limitation of oxygen, is simpler and more efficient, and has obvious therapeutic effects. By synthesizing hollow mesoporous manganese dioxide (MnO2) as a carrier, the nanoparticles are loaded with ABVN and encapsulated with PEG, which have excellent photothermal properties, can quickly heat up to the thermal decomposition temperature of ABVN under laser irradiation, can degrade and release ABVN in GSH and acidic environments, and generate a large number of alkyl radicals in a short period of time, with excellent treatment efficiency. This study breaks through the limitation of PDT caused by hypoxia in cancer cells and provides a promising research strategy for PDT treatment.
Song et al. (Fri,) studied this question.