Core-shell ZIF-67/MoS2 heterojunction microneedle accelerates wound healing via enhanced photothermal nanozyme-like activities

Bacterial infection impairs skin wound healing, leading to a growing healthcare challenge. Biomolecular microneedles are developed to deliver the antibiotics, offering desirable broad-spectrum antibacterial activity for accelerating wound healing. However, the application of antibiotics is limited owning to potential drug resistance. Reactive oxygen species (ROS) have recently emerged as the next-generation antibacterial agents, due to their distinctive advantages over antibiotics. It remains a challenge to endow the antibiotic-free microneedles with enhanced ROS-production and antibacterial efficiency. Herein, a core-shell ZIF-67/MoS 2 (ZM) heterojunction was synthesized using a hydrothermal method. Compared to ZIF-67 nanoparticles, ZM heterojunction not only generated more photo-generated electrons, but also reduced the energy loss during electron transfer. Thus, the photocatalytic potential of ZM heterojunction got significantly improved for ROS production. ZM heterojunction was integrated into the double-layer gelatin methacryloyl/ZM heterojunction (GMZM) microneedle. The photothermal nanozyme-like activity, broad-spectrum antibacterial activity, and biocompatibility of GMZM microneedle were verified. Under NIR irradiation, GMZM microneedle completed 98.02 ± 1.22 % of wound closure period within 16 days. The overall application effect of GMZM microneedle was not inferior to that of commercial wound dressings from 3 M Co., Ltd. In conclusion, this study developed an antibiotic-free GMZM microneedle demonstrating superior performances, showing great potential for the treatment of infected wounds.