Skin-permissible NIR-actuated hyperthermia using a photothermally responsive hydrogel membrane for the effective treatment of antibiotic-resistant bacterial infection

With the long-term widespread overuse of antibiotics, a large number of antibiotic-resistant bacteria have emerged and become a serious threat to healthcare systems. As an alternative strategy, near-infrared light (NIR)-actuated photothermal treatment has been developed for killing antibiotic-resistant bacteria. Although promising, the widespread applications of photothermal antibacterial platforms face great challenges due to the skin-harmful high laser irradiation. In this work, a novel NIR-responsive hydrogel membrane for effective photothermal sterilization upon light irradiation at skin-permissible intensity has been successfully prepared using a sodium alginate-based hydrogel membrane containing tannic acid-Fe(III) compounds (STF). The as-prepared STF displayed excellent mechanical capacity and fabricability. More importantly, the as-prepared STF revealed superior photothermal efficiency under a low-intensity NIR irradiation (0.3 W cm^-2), which was below the maximum permissible exposure of skin (0.33 W cm^-2). In addition, the STF showed the excellent performance of photothermal sterilization for MRSA both in vitro and in vivo. Furthermore, the STF showed good biocompatibility. Based on the simple synthesis method, outstanding mechanical properties, excellent photothermal sterilization performance and good biocompatibility, the STF could be a promising wound dressing for antibiotic-resistant bacterial infections.