Mechanically Active Adhesive and NIR-II-Activated Zwitterionic Hydrogel for Infected Maxillofacial Wound Repair and Abscess Elimination

Abstract

Maxillofacial wounds are often deep, irregularly shaped, and prone to scarring, which can cause significant psychological distress. Developing advanced wound dressings to address these issues is therefore very important. This study created a novel two-component zwitterionic hydrogel (PNPs@COL@Gel) by adding cationic polymer nanoparticles (PNPs) and type III collagen (COL), which demonstrates excellent mechanical strength and injectability, allowing it to conform smoothly to irregular maxillofacial wound shapes. In vitro tests showed that the PNPs had synergistic photothermal and photodynamic antimicrobial effects under near-infrared-II (NIR-II) laser irradiation, with killing rates of 96.9% and 97.5% against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli, respectively. The hydrogel also effectively breaks down biofilms and prevents their formation, while COL supports infected wound healing and helps prevent scarring. In vivo studies further demonstrated the therapeutic potential of this zwitterionic hydrogel. Mice with infected maxillofacial wounds healed faster, with the hydrogel penetrating deeply to treat subcutaneous pustular infections. Additionally, the hydrogel modulated the immune environment of wound tissues, encouraged epithelial cell growth, improved blood vessel formation, and greatly reduced scarring. These results offer a promising new approach for achieving scarless healing in maxillofacial wounds.

Keywords

cationic polymers / maxillofacial infection trauma / photothermal and photodynamic therapy / scarless healing / zwitterionic hydrogel

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2026 The Author(s). Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.