Study On Properties Of Chitosan Hydrogels Prepared Using Gamma Radiation

Chitosan is composed of N-acetyl-dglucosamine and d-glucosamine units linked by ?-(1–4) bonds and is insoluble in aqueous neutral and alkaline solution. This biopolymer is known for its wide biological properties. Chitosan derivative by quaternization can keep the excellent biological properties of chitosan. Because of the introduction of the quaternary ammonium salt groups, it also has good antibacterial property. Carboxymethyl chitosan as a water soluble chitosan also has many good properties, such as antibacterial, antiviral and anticancer properties.At present, most hydrogels are prepared via radical polymerization in the presence of crosslinking agents. However, the use of a chemical crosslinker can lead to structural inhomogeneity. These agents not only can affect integrity of the substance to be entrapped, but also with toxicity. In this study, quaternary ammonium chitosan(HACC), carboxymethyl chitosan(CMC) combined with polyvinyl alcohol(PVA) and polyethylene oxide(PEO) were mixed to form HACC/PVA/PEO hydrogels and CMC/PVA/PEO by employing ?-irridiation as free radical initiator. It is a environmental approach to fabricate hydrogels for biomaterial applications in mild preparing conditions. Chitosan and gelatin has the good clotting activity and biological compatibility. In this study, we introduced chitosan and gelatin in polyvinyl alcohol solutions to form chitosan/gelatin/poly(vinyl alcohol) hydrogels. The results showed the clotting activity of CS/Gel/PVA hydrogels is stronger than yunnan baiyao. The main researches are as followed:1.Carboxymethyl chitosan(CMC) Polyvinyl alcohol(PVA)/Polyethylene oxide(PEO) hydrogels were prepared by radiation crosslinking. The structure of the hydrogels was characterized by the use of FT-IR and SEM. The gel content, swelling ability, mechanical property and water evaporation rate of the hydrogels were also evaluated. The results revealed that CMC, PVA and PEO were perfectly compatible and interacted via the hydrogen bond. SEM showed that the hydrogel had a good three-dimensional network structure and the pores distributed uniformly in the sections of the materials. In vitro antibacterial activity assessment CMC/PVA/PEO hydrogel showed inhibitory effect against two bacteria(Staphylococcus aureus and Escherichia coli).2.Quaternary ammonium chitosan(HACC)/Polyvinyl alcohol(PVA)/Polyethylene oxide(PEO) hydrogels were prepared by radiation crosslinking. The structure of the hydrogels was characterized by the use of FT-IR and SEM. The gel content, swelling ability, mechanical property and water evaporation rate of the hydrogels were also evaluated. The results revealed that HACC, PVA and PEO were perfectly compatible and interacted via the hydrogen bond. SEM showed that the hydrogel had a good three-dimensional network structure and the pores distributed uniformly in the sections of the materials. In vitro antibacterial activity assessment HACC/PVA/PEO hydrogel showed pronounced inhibitory effect against two bacteria(Staphylococcus aureus and Escherichia coli). And the effect was stronger than CMC/PVA/PEO hydrogels. Therefore, this hydrogel has a promising potential to be applied as wound dressing.3.Chitosan(CS) /Gelatin(Gel)/Polyvinyl alcohol(PVA)hydrogels were prepared by radiation crosslinking. The structure of the hydrogels was characterized by the use of FT-IR.The influence of different weight ratios on properties including swelling ability and clotting activity was studied. The results showed the clotting activity of CS/Gel/PVA hydrogels is stronger than yunnan baiyao.