Spatiotemporally Light-Activatable Platinum Nanocomplexes for Selective and Cooperative Cancer Therapy.

Highly efficient nanoarchitectures are of great interest for achieving precise chemotherapy with minimized adverse side effects in cancer therapy. However, a major challenge remains in exploring a rational approach to synthesize spatiotemporally selective vehicles for precise cancer chemotherapy. Here, we demonstrate a rational design of bifunctional light-activatable platinum nanocomplexes (PtNCs) that produce dually cooperative cancer therapy through spatiotemporally selective thermo-chemotherapy. The Pt4+-coordinated polycarboxylic nanogel is explored as the nanoreactor template, which is exploited to synthesize bifunctional PtNCs consisting of a zero-valent Pt0 core and a surrounding bivalent Pt2+ shell with tunable ratios through a facile and controllable reduction. Without light exposure, chemotherapeutic Pt2+ ions are tightly bound on the surface of PtNCs, efficiently reducing undesirable drug leakage and nonselective damage on normal tissues/cells. Upon light exposure, PtNCs generate much heat via photothermal conversion from the Pt0 core and simultaneously trigger a rapid release of chemotherapeutic Pt2+ ions, thereby leading to the spatiotemporally light-activatable synergistic effect of thermo-chemotherapy. Moreover, PtNCs show enhanced tumor accumulation through the heat-triggered hydrophilicity-hydrophobicity transition upon immediate light exposure after injection, dramatically facilitating in vivo tumor regression through their cooperative anticancer efficiency. This rational design of spatiotemporally activatable nanoparticles provides an insightful tool for precise cancer therapy.