Modification of chitosan grafted with collagen peptide by enzyme crosslinking.

Free radicals are closely related to the occurrence and development of aging, cancer and inflammation. In this paper, the microbial transglutaminase (MTGase) was used as a catalyst to graft the collagen peptide (COP) molecules on the amino group of carboxymethyl chitosan sulfate (CMCS) to improve the antioxidant effects. FT-IR and NMR spectroscopy were used to confirm the successful grafting of COP to CMCS. Degree of substitution (DS) of CMCS-COP could be controlled by adjusting the reaction conditions. With the increase of concentration, the ability of each sample on scavenging capacity and reducibility tends to increase obviously. The results of anticoagulant experiments showed that the ability of CMCS and CMCS-COP with three different degrees of substitution on activated partial thrombin time (APTT) and prothrombin time (PT) values were all increased to compare with the control group. No relevant cytotoxicity against NIH-3T3 mouse fibroblasts was found for the copolymers. These results suggested that CMCS-COP would appear to be a promising candidate for wound dressing application.

Preparation and characterization of carboxymethyl chitosan sulfate/oxidized konjac glucomannan hydrogels.

Hydrogel wound dressing is a new type of biomaterial with performance that is better than traditional and biological dressings. It has been extensively researched and the application in the field of biomedicine is common. In this study, we developed a simple and nontoxic method for preparing a new type of composite hydrogel, which formed through the Schiff-base reaction between the aldehyde of oxidized konjac glucomannan (OKGM) and the amino of carboxymethyl chitosan sulfate (CMSS). The chemical structures of this composite hydrogel were characterized by transform infrared spectroscopy (FT-IR). The micro-morphology of hydrogels were analyzed by scanning electron microscopy (SEM). Meanwhile, the properties of composite hydrogels including gelation time, swelling ability, water evaporation rate, hemolytic potential and biological compatibility were also investigated in different means. The results gained from these studies show that this composite hydrogels have a series of properties such as short gelation time, good swelling ability, appropriate water evaporation rate, excellent hemocompatibility and well biological compatibility. Considering these excellent performance, this composite hydrogels can be used as a wound dressing to treat injured skin.