A multifunctional chitosan composite aerogel based on high density amidation for chronic wound healing

The management of chronic wounds remains a challenging clinical problem worldwide, mainly because of secondary infections, excessive oxidative stress, and blocked angiogenesis. Aerogel is a novel material with high porosity and specific surface area that allows gas exchange and rapid absorption of a large amount of exudate as well as loading bioactive molecules. Therefore, functional aerogel can be an ideal material for chronic wound treatment. The multifunctional aerogel (CG-DA-VEGF) was prepared by a simple and eco-friendly freeze-drying process combined with harmless EDC/NHS as crosslinking agents using chitosan and dopamine-grafted gelatin as raw materials. The physicochemical characterization revealed that the CG-DA-VEGF aerogel had excellent water absorption, water retention, and mechanical properties, and could release VEGF continuously and stably. In vitro experiments demonstrated that the CG-DA-VEGF aerogel exhibited effective antioxidant and antibacterial properties, as well as superb cytocompatibility. In vivo experiments further confirmed that the CG-DA-VEGF aerogel could significantly improve angiogenesis and re-epithelialization, and promote collagen deposition, thus accelerating wound healing with excellent biosafety. These results suggest that the as-prepared CG-DA-VEGF aerogel may be adopted as a promising multifunctional graft for the treatment of chronic wounds.