Chitosan membrane dressings toughened by glycerol to load antibacterial drugs for wound healing.

Transparent and flexible chitosan-based membranes containing antibacterial drugs were prepared through a casting/solvent evaporation method from suspension of chitosan floccule. To enhance mechanical properties, glycerin was incorporated into the floccule suspension to conjugate chitosan as a plasticizer. The mechanism of membrane formation is attributed to inter- and intro-hydrogen bonding between chitosan and glycerol molecules. The results showed that incorporation of glycerol has a significant influence on the properties of the chitosan membranes. With the increase of glycerol content, the tensile strength, swelling rate, water vapor permeability and wettability of membranes were significantly improved. In vitro enzymatic degradation revealed that the chitosan membrane had long-term stability regardless of the glycerol content. To enhance antibacterial properties, tetracycline hydrochloride (TH) and silver sulfadiazine (AgSD), representing the water-soluble and water-insoluble drug models, were integrated into the membranes, respectively. The results of controlled-release efficacy and inhibition zone indicate that the glycerol toughened chitosan membranes containing drugs have a promising future in treatment of bacterial infection as wound dressing.