Preparation of Sodium Alginate Hydrogels with Bioadhesive and Photothermal Effects to Suppress Bacterial Infection and Promote Wound Healing.

This study presents the development of a sodium alginate (SA)-based hydrogel (termed SPD hydrogel) with dual bioadhesive and photothermal properties to combat bacterial infection and enhance wound healing. The gel-forming polymer (SPD) was synthesized via amidation reactions between SA, dopamine (DA), and -aminophenylboronic acid (PBA). The hydrogel network was subsequently formed through dynamic borate ester bond cross-linking of the SPD polymers. Characterizations revealed that the SPD hydrogel exhibited substantial water absorption capacity (706.0 ± 10.6%) in pH 7.4 buffer and maintained excellent water retention (27.2 ± 5.5%) over 12 h at 25 °C. Importantly, in vitro cytotoxicity and hemolysis assays confirmed the hydrogel's biocompatibility, with no observable cellular toxicity or red blood cell lysis. These attributes enable the SPD hydrogel to establish a moist microenvironment that is highly favorable for wound regeneration. Notably, the DA- and PBA-modified SA backbone endowed the SPD hydrogel with exceptional photothermal efficiency and bioadhesive properties. In vitro antibacterial tests and in vivo cutaneous wound repair experiments demonstrated that the SPD hydrogel under near-infrared (NIR) laser irradiation (SPD + NIR group) exhibited potent bactericidal activity and significantly accelerated wound closure. Collectively, the SPD + NIR treatment represents a promising anti-infective hydrogel platform, offering innovative opportunities for advanced wound care applications.