Wound Healing Effect of the Chitosan Sponge

Chitosan is a polysaccharide obtained by deacetylating chitin which is the major constituent of the exoskeleton of crustaceous water animals. Chitosan has many useful biological properties such as biocompatibility, biodegradability, hemostatic effect, antimicrobial activity and the ease of chemical modification. In order to evaluate the efficacy of chitosan as a wound dressing material, authors prepared chitosan as a sponge form and compared it with ointment dressing material, amniotic membrane and hydrocellular dressing material through the animal experiment. Four round( 3 cm) full thickness skin defect were made bilaterally on the dorsolateral aspect of the New Zealand white rabbit's trunk and four groups of dressing material -chitosan sponge, ointment dressing material, amniotic membrane and hydrocellular dressing material-were applied on the wound and evaluated grossly and histopathologically. We compared gross finding by means of percentage of wound contraction, percentage of wound epithilization and percentage of wound healed by tracing the remained wound area every week and wound biopsy were performed every other day. Chitosan sponge group and amniotic membrane group show statistically higher percentage of wound contraction and higher percentage of wound healed than the other groups (p < 0.05). Hydrocellular dressing material group shows statistically lower percentage of wound epithelization than the others(p < 0.05). During the inflammatory phase (postwounding day 1-5) chitosan sponge group and amniotic membrane group absorbed exudate effectively and demonstrate less inflammatory cell infiltration, which induce faster angiogenesis and fibroblast proliferation than the other groups. This study suggest chitosan has a potential as a new dressing material because of high absorbency of exudate, promotion of wound contraction and reduction of inflammatory reaction during the inflammatory phase of wound healing.

A study on cytocompatibility of ion beam-irradiated chitosan sponges / 대한치주과학회지

Chitosan is a biodegradable and non-toxic material with a molecular weight of 800-1,500Kd which can be obtained in various forms with extraordinary chemical structures and biological characteristics of which enables it to be used in many fields as a biomaterial. Ion irradiation is a useful tool to modify chemical structures and physical properties of high molecular weight polymers. The basic hypothesis of this study is that when surface properties of chitosan in a sponge form are modified with ion beam-irradiation and cell adhesion properties of chitosan would improve and thereby increase the regenerative ability of the damaged bone. The purpose of this study was to illuminate the changes in the cytocompatibility of chitosan sponges after ion beam-irradiation as a preliminary research. Argon(Ar+) ions were irradiated at doses of 5x10(13), 5x10(15) at 35 keV on surfaces of each sponges. Cell adhesion and activity of alkaline phosphatases were studied using rat fetal osteoblasts. The results of this study show that ion beam-irradiation at optimal doses(5x10(13) Ar+ ion/cm2) is a useful method to improve cytocompatibility without sacrificing cell viability and any changing cell phenotypes. These results show that ion beam-irradiated chitosan sponges can be further applied as carriers in tissue engineering and as bone filling materials.