Study On Preparation Of Antimicrobial Chitosan Hydrogel Dressing And Their Properties

The wound dressing is a kind of medical products can take good care of injury that breaks the skin, it is necessary to cover the wounds with dressings to protect them and promote their healing. Hydrogel dressing is a kind of Modern wound dressings with excellent performance,they have excellent biocompatibility, good breathability and their appearance is transparent so that the wound recovery situation can be observed,their physical properties similar to soft tissue so that they are removable without causing trauma to the wound. But the antibacterial functions need to be strengthened.In this paper, we used PHMG which has a broad-spectrum antimicrobial property grafted to chitosan, carboxymethyl chitosan and used water soluble monomer to modified them, then the final product was prepared by chemical crosslinking. The schiff bases were characterized by elemental analysis, IR and XRD, the mechanical properties, water absorption and antimicrobial activity of products were tested. The results showed that the two kind of hydrogels exhibited high antibacterial activites against Staphylococcus aureus, The maximum tensile strength of PHMG-AA grafted chitosan hydrogel is 6.33MPa,and maximum water absorption rate the is 2720%; the maximum tensile strength of carboxymethyl chitosan hydrogel is 7.77MPa,and maximum water absorption rate the is 8130%They are two methods of synthesis of PHMG—AA which has reactivity by carbon-carbon double bond,one is acrylic acid to react with PHMG in solution;the other is acrylic acid and PHMG react with the participation of condensation agent. Copolymerization with chitosan, PHMG—AA, acrylic acid and Acrylamide as the main materials,then the final product was prepared by chemical crosslinking. From the results of the mechanical properties and water absorption,with the amount of initiator increased, the water absorption rate increased,but the tensile strength decreased; with the amount of crosslinking agent increased, he water absorption rate and the tensile strength increased.Carboxymethyl chitosan and PHMG react with the participation of condensation agent,then copolymerization with acrylic acid and acrylamide as the main materials. The final product was prepared by chemical crosslinking. From the results of the mechanical properties and water absorption, with the amount of PHMG increased, the water absorption rate increased.but the tensile strength decreased.Two kind of hydrogels exhibited high antibacterial activites against Staphylococcus aureus,but carboxymethyl chitosan hydrogel is better. The results of shaking flask method showed that when the concentration of PHMG—AA in the chitosan hdrogel was 2.0%, and shaking time was 60min, the growth inhibition against Staphylococcus aureus can reach 100%. When the concentration of PHMG—AA in the chitosan hdrogel was 3.0%, and shaking time was 50min, the growth inhibition against Staphylococcus aureus can reach 100%. When the concentration of PHMG in the carboxymethyl chitosan hdrogel was 1.5%, and shaking time was 60min, the growth inhibition against Staphylococcus aureus can reach 100%. When the concentration of PHMG in the carboxymethyl chitosan hdrogel was 3.0%, and shaking time was 30min, the growth inhibition against Staphylococcus aureus can reach 100%.