The Effects of Water Soluble Chitin on the Open Wound Healing in Rabbits

The purpose of this study was to evaluate effects of chitin on open wound healing in rabbits. Using 15 rabbits, a round, full thickness defect of skin with 2 cm in diameter was made on the ventral surface of the each ear. The experimental animals were divided into 3 groups: control group untreated group), base ointment group (group treated with base ointment), and chitin ointment group(group treated with water soluble chitin ointment). A total of 30 wounds were made and each subgroup was allocated 10. On the 7th day after initial wounding, each wound site including surrounding tissue was taken for macroscopic and histological observations. The amount of epithelialization and granulation tissue were measured by Image Analysis System. In macroscopic examination, larger amount of exudate and granulation tissue were observed in water soluble chitin ointment group compared to control and base ointment groups. In histological examination, water soluble chitin ointment group showed thick epithelium and larger amount of granulation tissue and fibroblast deposition. The areas of epithelialization and granulation tissue were significantly increased in water soluble chitin ointment group compared to control and base ointment groups. In conclusion, water soluble chitin accelerated open wound healing by accelerating reepithelization and granulation tissue formation.

The Effect of Poly-L-lysine on Proliferation and Differentiation of Preadipocyte in the Alginate Gels

Alginate is widely used for scaffold in tissue engineering. However, it has a limitation of cell proliferation due to the lack of cell-to-matrix adhesion. Authors were trying to find out that the alginate gel become an efficient three-dimensional biomatrix in case of mixing with poly-L-lysine (PLL). After harvesting preadipocyte from rat epididymal fat, the proper concentration of PLL for an efficient cell culture was examined in the alginate gel and the level of proliferation of cells were measured in order to find out the efficacy of PLL for the experimental group(alginate/PLL mixed gel) compared to the control group(alginate gel without PLL). In addition, the number of surviving cell was counted and the fat cell stained with oil-red O was observed on the 21st day of the culture. The preadipocytes in the alginate gel were most viable in the PLL concentration of 50 microgram/ml. After 4 days in culture, the level of cell proliferation and the number of preadipocytes were significantly higher in the experimental group than those in the control group. A small number of fat cells stained with oil-red O were starting to be appeared on the 14th day and the larger number of cells on the 21st day of the culture in two groups. These results suggest that PLL increased the proliferation of preadipocyte in the alginate gel through the enhancement of cell-to-matrix adhesion. It also shows that alginate has the advantage of inducing the differentiation of preadipocyte in case of alginate/PLL mixed gel. In conclusion, alginate/PLL mixed gel is turned out to be effective for making a three-dimensional biomatrix.

The Effect of Water Soluble Chitin on Wound Healing in Rats

The effect of water soluble chitin on wound healing in rats Chitin and chitosan, polysaccharides made up of polymeric N-acetyl glucosamine and D-glucosamine, are widely found in nature, forming skeletons of crustaceans and insects as well as components of bacteria cell walls. Chitin and chitosan have been known to have many useful biological properties such as biocompatibility, biodegradability, antimicrobial activity, and wound healing property. The key-point of practical use of chitin was making water soluble form. The purpose of this study was to compare the wound healing effect of water soluble with insoluble chitin. Full-thickness skin incision was made on the backs of the Sprague-Dawley rats. Three groups composed respectively with saline, water insoluble chitin and water soluble chitin were embedded in the wounds. The wound breaking strength and the collagen-hydroxyproline content of the wounded skins were measured and histological examination was performed at the time of 3, 7, 10 days respectively after the procedure. The tensile strength was maximum in case of water soluble chitin. The amount of collagen hydroxyproline was minimum in water soluble chitin. The wound treated with the water soluble and insoluble chitin was completely reepithelialized and granulation tissue in the wound was observed at 7 days after initial wounding. The arrangement of collagen fibers in the skin was orderly and similar to normal skin.

The Effect of Deacetylation of Chitin and Chitosan on Wound Healing in Rats

Chitin and chitosan, polysaccharides made up of polymeric N-acetly glucosamine and D-glucosamine, are widely found in nature, forming the skeletons of crustaceans and insects, as well as the components of bacteria cell walls. Chitin and chitosan have been known to have many useful biological properties such as biocompatibility, biodegradability, antimicrobial activity, and wound healing. There properties have been known to be different depending on the degree of deacetylation of chitin, but it has not yet been fully evaluated. The purpose of this study was to evaluate the wound healing effect by the degree of deacetylation. Full-thickness skin incision was made on the backs of Sprague-Dawley rats. Three concentrations of powder, comprising 90% chitin, 50% chitin and 10% chitin, were separately embedded in the wounds of 3 rat groups. The wound-breaking strength and the collagen-hydroxyproline content of the skin at the wound sites were measured and histological examination was performed at postoperative 3, 7, and 10 days. The 50% chitin group had the highest tensile strenght of all groups. But the 50% chitin and 90% chitin groups had the lowest collagen hydroxyproline levels among all groups. The wounds treated with 50% chitin powder were completely reepithelialized and granulation tissue in the wound was observed 7 days after initial wounding. The arrangement of collagen fibers in the skin was ordered and similar to normal skin The 50% chitin powder is considered to be the most efficient wound healing accelerator among different concentrations of chitin powder.

Carcinoma expleomorphic adenoma of lacrimal gland

Based on the histopathologic findings of the lacrimal gland tumor, the lesion is classified as either epithelial or nonepithelial tumor. 22% of lacrimal gland lesions were primary epithelial neoplasm. 4%of epithelial tumor of lacrimal glands were primary malignant tumor. Squamous cell carcinoma arising from pleomorphic adenoma of lacrimal gland is a very rare(0.4%). Inspite of surgical intervention, postoperative radiation and chemotherapy, the mortality and recurrence rate of the carcinoma ex pleomorphic adenoma of lacrimal gland is very high. We report a case of squamous cell carcinoma ex pleomorphic adenoma of lacrimal gland, which was completely removed via lateral orbitotomy with bicoronal incision and had no major complication or recurrence.