Light-activated PEG deshielding core-shell nanoparticles for enhanced chemo-photodynamic combination therapy.

Chemo-photodynamic combination therapy has attracted great attention as a promising cancer treatment strategy. However, the therapeutic efficacy has been limited by the low selectivity and penetration of therapeutic agents into the tumor. PEGylation is an effective strategy to enhance the stability and circulation times of nanoparticles, which improves the bioavailability of encapsulated drugs. However, such PEGylation nanomedicines also decrease cellular uptake efficiency. Herein, we developed a smart nano-drug delivery system with PEG deshielding and charge reversal performance triggered by external light irradiation, which can not only enhance tumor selectivity and tumor penetration but also combine photodynamic therapy and chemotherapy for better tumor treatment effects, contributed by the use of core-shell nanoparticles with positively charged complex Pt(IV) prodrugs and photosensitizers.