Animal grafting experiment of reconstructive tissue engineered artificial skin made by chitosan as stromal scaffold / 中国组织工程研究

ABSTRACT

BACKGROUND: Skin transplantation is the most effective conventional method to cure large area full-thickness skin damage caused by empyrosis or some diseases, but present deficiency of skin donator is the largest barrier in front. The most ideal way to solve this problem is to use tissue-engineering skin reconstructed by self-skin cells as seed cells.OBJECTIVE: To investigate the effects of tissue engineered artificial animal skin in animal grafting experiment.DESIGN: A randomized controlled trial SETTING: Institute of frontier medical sciences and department of dermatology in a university.MATERIALS Study was performed in the Cell-Engineering Institute of Jilin University from September 1998 to July 2001. Totally 20 newborn Wistar rats and 24 8-week old male nude mice were selected into our study.METHODS: Full-thickness wounds(diameter 20 nn) were made on the backs of twenty-four nude mice to establish full-thickness skin defect animal model for grafting by the tissue-engineered reconstructive artificial skin made by chitosan(CH) as stromal scaffold. Twenty-four 8-week old nude mice were divided into artificial skin (AS) group, chitosan membrane(CH) group and control group (CG). All wounds were covered with AS, CH or petrolatun gauze correspondingly. The wounds of each groups were observed daily,techniques like histology and infrared-ray scan were used for a dynamical surveillance on the 3rd, 7th, 14th and 21st days.MAIN OUTCOME MEASURES: ① general observation; ② blood supply in recipient area under infrared-ray observation; ③ histological observation.RESULTS: Transplanted AS had a favorable fusion between tissue-engineered skin and self-skin on the 3rd day after grafting with a few of ingrowths of capillaries. The color of the AS was closed to self-skin. The capillaries gradually increased in the grafts over time. The new epidermis was clearly consisted of stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. Keratinization enhanced with exfoliation. Cells in dermis increased and the scaffold gradually degraded. The secreted extracellular matrix increased as well. On the 14th day after grafting, the wounds almost recovered.The color of the grafted artificial skin was more similar to the nature skin with very little scaring, which indicated that a second grafting was unnecessary. The scabs did not completely fall off in CH group until the 14th day, and the wound was not healed. The color was darker than that of AS group. The scabs fell off in CG, and the wounds were big and deep with dark red color.CONCLUSION: The new reconstructive tissue-engineered artificial skin with CH as stromal scaffold has good histocompatibility, which can be applied in grafting for full-thickness wounds.