A high-performance, self-adaptive sprayable hydrogel dressing based on zinc alginate, quaternized chitosan, and gallic acid for wound healing applications.

Abstract

Conventional wound dressings often fail to conform adequately to irregular wound beds, thereby limiting their therapeutic efficacy. Therefore, the development of multifunctional dressings with self-adaptive capabilities is crucial for improving the quality of wound healing. Herein, we developed a spray-crosslinking strategy to construct a multifunctional hydrogel dressing by compounding natural polymers‑sodium alginate (Alg), quaternized chitosan (QAC), and gallic acid (GA). Through a dual-nozzle spray system, the dressing was formed via in situ and rapid crosslinking with zinc ions (Zn2+). This process was accomplished within 10 s, achieving excellent self-adaptive conformity to the wound contours. Benefiting from the combined effect of electrostatic interactions and Schiff base crosslinking, the hydrogel exhibited significantly improved mechanical strength and structural stability compared to pure zinc alginate hydrogel. Functionally, the synergistic effect of QAC and Alg-Zn endowed the dressing with broad-spectrum antibacterial activity, with maximum inhibition zones of 6 mm, 8 mm, and 2 mm against E. coli, S. aureus, and P. aeruginosa, respectively. Additionally, the incorporation of GA provided superior reactive oxygen species (ROS) scavenging capabilities. In a murine full-thickness skin defect model, the dressing significantly accelerated wound healing, with a closure rate reaching 98.15% by day 15, and promoted collagen deposition and tissue regeneration. In summary, the self-adaptive sprayable hydrogel dressing developed in this work integrates rapid molding, broad-spectrum antibacterial, antioxidant, and healing-promoting functions, offering a promising new strategy for the effective treatment of complex clinical wounds.