Preparation and antibacterial properties of an AgBr@SiO/GelMA composite hydrogel.

Pure gelatin hydrogels lack antibacterial function and have poor mechanical properties, which restrict their application in wound dressings. In this study, nanosized silver bromide-doped mesoporous silica (AgBr@SiO) microspheres with hollow structures were prepared by a modified Stober method. The novel microspheres can not only release silver ions to treat bacteria but also release drugs to treat skin wound. Furthermore, AgBr@SiOmicrospheres were modified with propyl methacrylate, incorporated into methacrylated gelatin (GelMA), and crosslinked by UV light to prepare AgBr@SiO/GelMA dressings consisting of composite hydrogels. The results showed that the AgBr@SiOmicrospheres could enhance the mechanical properties of the hydrogels. With the increase in the AgBr@SiOconcentration from 0.5 to 1 mg ml, the dressings demonstrated effective antimicrobial activity against bothand. Furthermore, full-thickness skin woundswound healing studies with Sprague-Dawley rats were evaluated. When treated with AgBr@SiO/GelMA containing 1 mg mlAgBr@SiO, only 15% of the wound area left on day 10. Histology results also showed the epidermal and dermal layers were better organized. These results suggest that AgBr@SiO/GelMA-based dressing materials could be promising candidates for wound dressings.