A Hydrogel with Low-Temperature Photothermal Therapy and ROS Scavenging Capability for Healing Infected Diabetic...

Photothermal therapy (PTT) in antimicrobial treatment of diabetic wounds faces the challenge of damaging normal tissues with high temperatures. In this study, mesoporous polydopamine (MPDA) as the core, encapsulated by Zeolitic Imidazolate Framework-8 (ZIF-8) shell, and loaded with berberine (BBR) are used to fabricate MPDA@ZIF-8/BBR core-shell nanoparticles (NPs). Then, those NPs are incorporated into hydrogels formed by reacting carboxymethyl chitosan (CMCS) with oxidized hyaluronic acid (OHA) via Schiff base chemistry, creating a photothermal nanocomposite hydrogel capable of scavenging ROS (Gel- MPDA@ZIF-8/BBR). The hydrogel achieves low-temperature PTT antimicrobial activity by controlled degradation under the weak acidic conditions of the bacterial infection microenvironment and simultaneous release of BBR and Zn²⁺, combined with the mild photothermal effect of MPDA. The released BBR synergistically enhances the photothermal effect by inhibiting bacterial community sensing, effectively disintegrating the bacterial biofilm. More importantly, the composite hydrogels showed good biocompatibility, effectively inhibited the wound inflammatory response, and significantly accelerated wound healing, which achieved low-temperature PTT antibacterial therapy and has the potential to treat diabetic-infected chronic wounds.