Establishment Of Skin Defect Animal Models And Study On Skin Defect Restoration By Transplantation Of Tissue Engineered Composited Skin

Acute and chronic skin defects of different causes are difficult problems to resolve all along, and especially full-thickness skin defect and chronic ulcer represent the major health burden. Autograft and autotransplant, the routine treatment in clinic, are limited by skin supply and result to new hurt of supply sections. Due to the different causes and wound biology, our understanding of defective types seems to be instructive to the development of treatments. Therefore, development of reproducible models of different defects was of importance. Standardization of animal models hasn't established both inland but overseas. In my study, the reproducible models of burn defect, pressure ulcer and acute medicational ulcer were developed and characterized in the skin of swine on the principles of recent international advancing methods. Whereafter, tissue engineered composited skin was cultured in vitro to transplant in the different skin defective types of animal model.1. A reproducible model of burn defect was developed and characterized in the skin of swine. The degree of burn was depended on the temperature, time and pressure of the heater, which can be controlled through the numericalcontrol burn instrument I developed based on the references. Through this experiment, the final conclusion was: Degree Ⅲ burn defect can be developed in the 20cm~2 skin on the back of swine, under 100℃, 25 seconds, 1 kg pressure of the numerical control burn instrument.2 . A reproducible model of pressure ulcer was developed and characterized in the skin of swine. The form of ulcer was resulted of press, cut, friction and humidification, maily depended on the protuberance and , duration of pressure. Pressure ulcer was created in a 20 cm~2 region of dorsal skin in swine by compressing skin under different pressures and durations using a pressure applicator. After the examination of the post-operational effect, I obtained the result that the Ⅲ ulcer can be created under the condition of pressure of 5 kg and duration of 12h.3. A reproducible model of acute medicational ulcer was developed and characterized in the skin of swine. The character, concentration and effective time of medicine were the main forming factors of acute medicational ulcer. Based on relating references, arsenic agent was adopted to prepare the ulcer in the skin of swine, and affirmed the wound care of post-operation and even aggravation of it without any treatment.4. Transplantation experiment of tissue engineering skin to burn wound. After 24 hours of burn wound prepared in the skin of swine, tissue engineering skin was transplanted, contrasting with autograft and blank. The investigation of post-operation proved transplanted tissue engineering skin had double-deck structure of dermis and epidermis, so its histological form was similar to natural skin. And the net of blood vessels and structure of fiber was recovery gradually after two weeks post-operation.5. Transplantation experiment of tissue engineering skin to pressure ulcer wound. Firstly, ulcer wound was prepared by the method of experiment 2; then infection was controlled, the full-thickness and dermis tissue engineering skin were transplanted in the skin of swine finally. The histopathological...