活性真皮替代物的体内外实验

背景:真皮替代物是构建组织工程皮肤替代物的基础。目的:构建具有活性的组织工程真皮替代物,并进行体内外实验。方法:胶原凝胶和成纤维细胞制成活性真皮替代物,并进行组织学观察。将活性真皮替代物移植于BALB/c裸鼠背部全层皮肤缺损模型,4周后取材观察其组织学变化。结果与结论:①体外实验:随培养时间延长,活性真皮替代物直径逐渐减小,韧性增加,至14d时为原直径18.2%,可夹持提起而不破碎。成纤维细胞在胶原凝胶内成活良好,保持良好的细胞外基质分泌活性,Ⅰ型胶原蛋白、纤维连接蛋白、血管内皮生长因子均阳性表达。②体内实验:活性真皮替代物覆盖创面4周后被表皮覆盖,表皮分层清晰,但较正常表皮层厚;真皮层中成纤维细胞仍存活并发挥作用,胶原纤维排列有序,呈匀质性,无分层,真皮内炎性细胞少见,有成熟血管,缺乏毛囊和皮脂腺。表明应用胶原凝胶三维培养成纤维细胞能构建出具有活性的组织工程真皮替代物,移植创面后可促进其表皮化。

In vivo and in vitro experiments of living derm substitute

BACKGROUND：Derm substitute is the foundation of constructing tissue engineering skin. OBJECTIVE：To construct the living derm substitute and to perform the in vivo and in vitro relevant experiments. METHODS：Collagen gel and fibroblasts were mixed to construct the living derm substitute and then histological observation was performed in vitro. Living derm substitutes were transplanted onto the back wounds of BALB/c nude mice with full-thickness skin defects, and the histological observation was performed after 4 weeks. RESULTS AND CONCLUSION：①In vitro experiment：With the cultured time gone, the diameter of the living derm substitute reduced gradually, and the toughness increased. Up to 14 days, the diameter decreased to the original diameter of 18.2%, which was not broken under clamping and lifting. Fibroblasts grew well in the collagen gel and maintained secretory activity. TypeⅠcollagen, fibronectin and vascular endothelial growth factor were all positively expressed in the collagen gel. ②In vivo experiment：At 4 weeks after living derm substitute transplanted onto the wounds, the living derm substitutes were covered by epidermis with clear stratification that was thicker than normal skin. Fibroblasts in the dermis were alive and worked, and the collagen fibers arranged orderly which were homogeneous and non-hierarchical. Rare inflammatory cells could be seen in the dermis, mature blood vessels could be seen, and there lack of hair follicles and sebaceous. Living derm substitute could be constructed by fibroblasts in three-dimensional type Ⅰcollagen gel culturing, which could promote the epithelialization after transplanted onto the wound.