毛囊单位移植促进创面愈合

Effect of hair follicle unit transplantation on wound healing

背景:皮肤创伤后毛囊真皮鞘细胞可能直接参与真皮损伤的修复或者转化为成纤维细胞参与皮肤修复。目的:建立大鼠毛囊单位创面移植模型,对创面愈合过程中真皮成分的生长进行组织学和超微结构观察和分析,拟探索毛囊组织参与创面真皮愈合的潜力。设计、时间及地点:对照动物实验,于2007-09/2008-04在复旦大学附属中山医院完成。材料:体质量为200～250g的18只SD大鼠用于制备毛囊单位创面移植模型及微粒表皮移植模型。方法:剪取毛囊单位创面移植组大鼠单侧鼠须垫皮肤,伤口原位缝合,用锐器分割鼠须垫毛囊,切取带有毛囊乳头、毛囊周围组织及部分表皮的毛囊单位复合组织。将毛囊单位植入制备好的创面上,每个创面放入5～7个毛囊单位;切取微粒表皮移植组大鼠全层皮肤中剪切取表皮和部分真皮层皮肤,并修剪成约3mm×3mm大小,原位植入创面中,每个创面放入5～7个微粒皮片。主要观察指标:第2,3,4,5周取创面标本,行苏木精-伊红染色、苦味酸天狼猩红染色,制作碱性水处理的扫描电镜标本,在偏振光显微镜和扫描电镜下观察,用图像软件处理并分析。结果:创面愈合的初期,两组的创面分泌的胶原基质的类型与量均无明显差异。但随着创面愈合的进行,创面中胶原基质发生重塑性的改变,两者创面中基质的Ⅲ型胶原开始减少,Ⅰ型胶原相应增加。在创面形成后第5周时观察到毛囊单位移植组与微粒表皮移植组的Ⅰ型和Ⅲ型胶原的比值均有不同程度增加,对照组增加更明显,二者差异显著(P<0.05)。用碱性水处理的扫描电镜方法对晚期创面基质的观察也发现毛囊单位移植的创面基质中胶原纤维由粗细不等的纤维交织而成,胶原纤维的排列较致密有序,仍保持了一定的方向性。结论:在创面形成后期毛囊单位移植的愈合创面中胶原比值更接近正常皮肤,胶原排列更整齐有序,提示毛囊单位创面移植提高创面愈合的长期效果好。

BACKGROUND： After trauma, dermal sheath cells can directly participate in the repair of dermal injury or transfer into fibroblasts, which join in skin repair. OBJECTIVE： To establish models of rat hair follicles, to investigate and analyze the histology and ultrastructure of dermal component during wound healing, and to explore the potential of hair follicle tissues for dermal healing. DESIGN, TIME AND SETTING： The control animal experiment was conducted at the Zhongshan Hospital Affiliated to Fudan University from September 2007 to April 2008. MATERIALS： Eighteen Sprague Dawley （SD） rats weighing 200 250 g were used to prepare models of hair follicle units and mini-epidermis transplantation on wound. METHODS： Rat hair follicle units were cut from lateral vibrissa pad skin. Incision was sutured. Vibrissa pad hair follicles were cut with a sharp tool to collect hair follicle with papilla, surrounding tissues and partial surface. Hair follicle units were implanted into the wound, 5-7 units in each wound. Epidermis and some dermic skin were obtained from full-thickness skins of rats in the mini-epidermis transplantation group, and then trimmed into 3×3 mm size, 5 7 mini-epidermis in each wound. MAIN OUTCOME MEASURES： The wound specimens were obtained at the 2^nd, 3^rd, 4^th, 5^th weeks postoperatively. Hematoxylin-eosin stain, Picric-sirius red stain and AWMSEM （alkaline water maceration scanning electron microscope） were performed, and observed under a polarization microscope and scanning electron microscope. The images were processed and analyzed with computerized image analysis system. RESULTS： No significant difference in type and quantity of collagen matrix was detected in both groups at the early phase after wounding. The type Ⅲ collagens kept reducing as time elapsed, but type Ⅰ increased. At 5 weeks after wounding, the ratios of types Ⅰ and Ⅲ collagen increased in both groups, especially in the control group. Significant differences were detected between both groups （P 〈 0.05）. The observation with scanning microscope showed that the collagen fibers were braided into bundles in different sizes, the bundles exhibited parallel and tight. CONCLUSION： The ratio collagen fiber in follicle unit transplantation group is much more alike to normal skin, and the arrangement of collagens seems to be more ordered. This indicates that follicle unit transplantation can improve the quality of wound healing.