pH- and Near-Infrared Light Dual-Responsive Hydrogel Microneedles Incorporating Polydopamine-Based Curcumin-Loaded Nanoparticles for Antibacterial and Oxidative Injury Protection.

Bacterial infection and persistent oxidative stress can impair wound healing and limit the efficacy of conventional antibacterial therapies. Here, we developed a pH- and near-infrared (NIR) light-responsive polymer hydrogel microneedle (PHMN) system by incorporating curcumin-loaded polydopamine particles (PDA@CUR) into photo-crosslinked methacrylated hyaluronic acid (HAMA) microneedles with a poly(vinyl alcohol) (PVA) backing layer. The synthesized CUR-loaded PDA nanoparticles (PDA@CUR) exhibited uniform spherical morphology, efficient CUR loading, and pH- and NIR light-responsive drug release. The fabricated PHMN/PDA@CUR patch displayed a well-defined array, sufficient mechanical strength, and efficient photothermal conversion under NIR irradiation. The patch could effectively inhibit both E. coli and S. aureus, with NIR irradiation further enhancing antibacterial activity. This PHMN-based system also exhibited favorable cytocompatibility and significantly alleviated H2O2-induced cellular oxidative injury. Overall, the PHMN/PDA@CUR patch integrate localized drug delivery, NIR-enhanced photothermal antibacterial activity, and cellular protection, providing an in vitro proof-of-concept platform for localized management relevant to infected wounds.