Polyphenol-assisted albumin-based biomineralization nanocarriers with NIR-II-targeted photothermal performance towards broad-spectrum radical scavenging.

The oxidative stress is a state of imbalance in the body's oxidative balance, which can cause or worsen many diseases. Several studies have focused on the direct scavenging of free radicals, however, the strategy of precisely controlling antioxidant activities remotely and spatiotemporally has rarely been reported. Herein, we report a method inspired by the albumin-triggered biomineralization process with polyphenol-assisted strategy to prepare nanoparticles (TA-BSA@CuS) with NIR-II-targeted photo-enhanced antioxidant capacity. Systematic characterization demonstrated that the introduction of polyphenol (tannic acid (TA)) induced the formation of a CuO-doped heterogeneous structure and CuS nanoparticles. Compared with the TA-free CuS nanoparticles, TA-BSA@CuS exhibited excellent photothermal property in the NIR-II region, which is ascribed to the TA-induced Cu defects and doped CuO. Moreover, the photothermal property of CuS improved the broad-spectrum free radical scavenging efficiency of TA-BSA@CuS, and its HO clearance rate increased by 47.3% under NIR-II irradiation. Meanwhile, TA-BSA@CuS exhibited low biological toxicity and intracellular free radical scavenging ability. Moreover, the excellent photothermal property of TA-BSA@CuS endowed it with good antibacterial ability. Therefore, we expect that this work will pave the way for the synthesis of polyphenolic compounds and the improvement in their antioxidant capacity.