Highly biocompatible, antioxidant and antibacterial gelatin methacrylate/ alginate - Tannin hydrogels for wound healing

Gelatin (Gel) hydrogels are widely utilized in various aspects of tissue engineering, such as wound repair, due to their abundance and biocompatibility. However, their low strength and limited functionality have constrained their development and scope of application. Tannic acid (TA), a naturally occurring polyphenol found in plants and fruits, has recently garnered interest as a crosslinking, anti-inflammatory, and antioxidant agent. In this study, we fabricated novel multifunctional gelatin methacrylate/alginate-tannin (GelMA/Alg-TA) hydrogels using chemical and physical crosslinking strategies with gelatin methacrylate (GelMA), alginate (Alg), and TA as the base materials. The GelMA/Alg-TA hydrogels maintained a stable three-dimensional porous structure with appropriate water content and exhibited excellent biocompatibility. Additionally, these hydrogels demonstrated significant antioxidant and antibacterial properties and substantially promoted wound healing in a mouse model of full-thickness skin defects by modulating inflammatory responses and enhancing granulation formation. Therefore, our study offers valuable insights into the design principles of novel multifunctional GelMA/Alg-TA hydrogels, highlighting their exceptional biocompatibility, antioxidant, and antibacterial properties. GelMA/ Alg-TA hydrogels are promising candidates for wound healing applications.