No abstract

Much effort has been focused on novel nanomedicine for cancer therapy. However, tumor hypoxia limits the efficacy of various cancer therapeutics. Herein, we constructed a self-sufficient hybrid enzyme-based silk fibroin hydrogel system, consisting of Pt-decorated hollow Ag−Au trimetallic nanocages (HGN@Pt) and glucose oxidase (GOx), to supply O 2 continuously and consume glucose concurrently and, thereby, synergistically enhance the anti-cancer efficacy of a combined starvation and photothermal therapy operating in a hypoxic tumor microenvironment. Thanks to the cooperative effects of the active surface atoms (resulting from the island-like features of the Pt coating), the intrinsically hollow structure, and the strain effect induced by the trimetallic composition, HGN@Pt displayed efficient catalase-like activity. The enhancement in the generation of O 2 through the decomposition of H 2 O 2 mediated by the as-designed nanozyme was greater than 400% when compared with that of hollow Ag−Pt bimetallic nanospheres or tiny Pt nanoparticles. Moreover, in the presence of HGN@Pt, significant amounts of O 2 could be generated within a few minutes, even in an acidic buffer solution (pH 5.8−6.5) containing a low concentration of H 2 O 2 (100−500 μM). Because HGN@Pt exhibited a strong surface plasmon resonance peak in the near-infrared wavelength range, it could be used as a photothermal agent for hyperthermia therapy. Furthermore, GOx was released gradually from the SF hydrogel into the tumor microenvironment to mediate the depletion of glucose, leading to glucose starvation-induced cancer cell death. Finally, the O 2 supplied by HGN@Pt overcame the hypoxia of the microenvironment and, thereby, promoted the starvation therapeutic effect of the GOx-mediated glucose consumption. Meanwhile, the GOx-produced H 2 O 2 from the oxidation of glucose could be used to regenerate O 2 and, thereby, construct a complementary circulatory system. Accordingly, this study presents a self-sufficient hybrid enzyme-based system that synergistically alleviates tumor hypoxia and induces an anti-cancer effect when combined with irradiation of light from a near-infrared laser.

No abstract

No abstract

No abstract