Biodegradable all-natural hydrogel–mesh composite for wet tissues adhesion and infected wound healing

The application of meshes in surgery is severely limited by complications associated with the non-absorbable nature, the lack of bioactivities, and the need of sutures and/or staples to fix meshes on tissues. In this contribution, a self-adhesive hydrogel-mesh composite (HMC) with biodegradability and multiple bioactivities was developed to address these issues and meet the clinical requirement. In this HMC system, GelMA hydrogel network was first macrotopological entangled with the fibers of a natural small intestinal submucosa (SIS) meshes, and then strengthened by soaking in a multi-functional H-bond provider (i.e., tannic acid, TA) solution to form G/SIS-TA composite. The pyrogallol groups of the TA molecules endow G/SIS-TA with excellent wet adhesiveness (shear strength: ∼60 kPa), antioxidant, and antibacterial ability. The G/SIS-TA was also found to exhibit excellent biodegradability, biocompatibility, and immunoregulatory activity. In vivo, G/SIS-TA significantly decrease the bacterial burden in a mouse peritonitis infection model and promote the healing of infected full-thickness rat skin wounds. This work not only reports a novel SIS-based HMC which was efficient in treating infected wounds, but also offers an innovative strategy of the development of self-adhesive bio-patch for various biomedical applications.