Local delivery of MoS2/FeS2 heterojunction by biomolecular microneedles for multimodal therapy of infected wounds

Infected wound healing is obstructed by not only bacterial infection, but also the formation of bacterial biofilm. Over the past decades, researchers have developed a large number of wound dressings with broad-spectrum antibacterial activity, yet less progress has been achieved in anti-biofilm wound dressings. Thus, the treatment effect of infected wounds remains significantly limited. Herein, a MoS2/FeS2 (M/F) heterojunction was successfully synthesized using a hydrothermal reaction, and then the tips of methacrylate Gelatin (GelMA) microneedles were immobilized to obtain a series of double-layered GMF-n microneedles (n = 0, 0.5, 1 and 4, corresponding to the content of M/F heterojunction). The results showed that GMF-n microneedles exhibited relatively good biocompatibility and a range of photothermal, photodynamic and photocatalytic activities with pro-oxidative potential. In particular, the combination of GMF-1 microneedles and mild photothermal therapy (MPTT) could generate bacteria-toxic ROS for antibacterial and anti-biofilm applications, and accelerate S. aureus-infected wound healing via multiple approaches, such as diminishing tissue inflammatory, promoting cell proliferation, vascularization, and collagen deposition. The effectiveness and safety were proved to be robust. This study not only developed the M/F heterojunction-laden, double-layered GMF-1 microneedles with desirable clinical translational value, but also proposed a universal strategy of multimodal therapy in the treatment of infected wounds.