Primary observation of therapeutic effect of collagenase on hypertrophic scar / 中国组织工程研究

ABSTRACT

BACKGROUND: Hypertrophic scar results from imbalance between local collagen synthesis and degradation and abnormal aggregation of collagen after burn and trauma.OBJECTIVE: To observe the effects of collagenase on collagen degradation in nude mice with graft of hypertrophic scar and its therapeutic effects on hyertrophic scar.DESIGN: Controlled experiment was designed.SETTING: Department of Rehabilitation and Physical Therapy,Southwest Hospital, Third Military Medical University of Chinese PLA MATERIALS The experiment was performed in Experimental Center of the Third Military Medical University of Chinese PLA from July 1995 to April 1997, in which, 10 specimens of hypertrophic scar were employed, collected from the removed hypertrophic scars in Department of Plastic Surgery.All of patients were in the known before the operation. Experimental animals were 15 BACB/C nude mice, of which, 8 mice were male and 7 mice female.Totally 15 mice were grafted with hypertrophic scar tissue, 10 mice of which were survived after once graft; with second graft in the rest mice, 2 mice were survived and 3 mice were dead. The survival nude mice were randomized into experimental group and the control, 6 mice in each one.METHODS: The removed hypertrophic scars in plastic operation were grafted in the wound on the dorsum of nude mice to establish graft model of hypertrophic scar. In experimental group, 1% collagenase was injected locally in scar tissue; in the control group, collagease solvent was injected locally, once a week, for 4 weeks totally. After treatment, the materials were collected for macrogcopic observation and observation and analysis with optic and electronic microscopes.scar tissue before and after treatment.RESULTS: Twelve nude mice were survived after scar graft and all of them entered result analysis, 6 mice of which were in experimental group was smaller in size, thinner in thickness and softer in quality compared staining, Van Gieson's collagenous fiber staining and compound staining on slices, it was displayed that in experimental group, dermal layer became thin, collagenous fiber was unclear in structure and disperse in arrangement, but in the control, the dermal layer of scar tissue was hypertrophic microscopic observation, in experimental group, collagenous fibers were destroyed and unclear in structure, but in the control, collagenous fibers were disturbed in arrangement with distinct strips and clear structure.CONCLUSION: Collagenase degrades collagen of hypertrophic scar,lessens and softens scar, suggesting that local injection of collagease is probably a good therapy for hypertrophic scar.