Supramolecular Hydrogel Microneedles Achieve a Three-in-One Antibacterial Wound Treatment

Bacterial infections lead to delayed wound healing and pose a significant threat to health. The current antimicrobial treatments face significant challenges, including bacterial resistance, poor biofilm penetration, and suboptimal therapeutic efficacy. To address these limitations, a Supramolecular hydrogel Microneedle (MN) is designed to achieve a three-in-one (photothermal effect/ H₂S gas/phage) effect for infected wound treatment. Briefly, the tannic acid (TA)/FeS complex within the Supramolecular casein/gelatin hydrogel enabled NIR-responsive photothermal effects, while T4 phages loaded in the system are directly delivered to the wound via MN arrays to target bacterial infection. Additionally, TA's antioxidative capacity and the release of H₂S from FeS particles under physiological conditions efficiently scavenged reactive oxygen species and promoted M2 macrophage polarization. In vivo studies demonstrated that the MNs significantly accelerated wound closure by ≈61.5% and alleviated inflammation in diabetic-infected mouse models. When compared with the control group, the MNs achieved an antibacterial rate of 95%. This Supramolecular hydrogel MN system offers a promising strategy for multifunctional wound healing by integrating photothermal, chemical, and phage therapies.