Characterization of an oxidized alginate-gelatin hydrogel incorporating a COS-salicylic acid conjugate for wound healing.

In the present study, chitooligosaccharide (COS) and salicylic acid (SA) conjugates were synthesized using HO-induced grafting polymerization and oxidized alginate (OA) and gelatin hydrogels were fabricated using Schiff's base reaction. To confirm the synthesis and improved activity of the COS-SA conjugates, polyphenol assays, ultraviolet absorbance, NMR, and antioxidant activity tests were all conducted. The results showed that the COS-SA conjugates were completely synthesized and improved antioxidant activity. OA was synthesized using a periodate method and a hydrogel was obtained at a mixed ratio of 3:7 via crosslinking between the aldehyde group of the OA and the amine groups of gelatin with COS-SA conjugates. In a cytotoxicity and wound healing model, the hydrogels with COS-SA conjugates did not exhibit cytotoxicity and exhibited wound healing activity in a mouse model. These results provide evidence that OA and gelatin hydrogels with a COS-SA conjugate can be successfully used for wound healing applications.