Department of Hand Surgery, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, China; Department of Burns, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, China.
J Mech Behav Biomed Mater. 2014 Jan;29:114-25. doi: 10.1016/j.jmbbm.2013.08.031. Epub 2013 Sep 12.
Dermal substitutes are used as dermal regeneration templates to reduce scar formation and improve wound healing. Unlike autografts, dermal substitutes lack normal vascular networks. The increased distance required for diffusion of oxygen and nutrients to the autograft following interpositioning of the substitute dramatically affects graft survival. To evaluate the effect of collagen-chitosan scaffold thickness on dermal regeneration, single-layer collagen-chitosan porous scaffolds of 0.5-, 1- and 2-mm thicknesses were fabricated and used to treat full-thickness wounds in a one-stage grafting procedure in a rat model. Skin-graft viability, wound contraction, histological changes, and wound tensile strength were evaluated. The results indicated that the distance for the diffusion of oxygen and nutrients to the autograft in the 2-mm-thick scaffold provided less support for graft take, which resulted in graft necrosis, extensive inflammatory reaction, marked foreign-body reaction (FBR), rapid scaffold degradation, and abnormal collagen deposition and remodeling. In contrast, the thinner scaffolds, especially of that 0.5-mm thickness, promoted earlier angiogenesis, ensuring skin-graft viability with a mild FBR, and ordered fibroblast infiltration and better collagen remodeling. It can be concluded that collagen-chitosan porous scaffolds with a thickness of <1mm are more suitable for dermal regeneration and can be used as dermal templates for treatment of dermal defects using a one-stage grafting procedure.
皮肤替代物被用作皮肤再生模板，以减少疤痕形成并改善伤口愈合。与自体移植物不同，皮肤替代物缺乏正常的血管网络。替代物插入后，氧气和营养物质扩散到自体移植物所需的距离增加，这极大地影响了移植物的存活。为了评估胶原-壳聚糖支架厚度对皮肤再生的影响，制备了 0.5、1 和 2mm 厚的单层胶原-壳聚糖多孔支架，并在大鼠模型中采用一次性移植程序治疗全厚伤口。评估了皮肤移植物的存活率、伤口收缩、组织学变化和伤口拉伸强度。结果表明，2mm 厚支架中氧气和营养物质扩散到自体移植物的距离对移植物的支撑作用较小，导致移植物坏死、广泛的炎症反应、明显的异物反应（FBR）、快速的支架降解以及异常的胶原沉积和重塑。相比之下，较薄的支架，尤其是 0.5mm 厚的支架，更早地促进了血管生成，确保了皮肤移植物的存活，异物反应轻微，成纤维细胞浸润良好，胶原重塑更好。可以得出结论，厚度<1mm 的胶原-壳聚糖多孔支架更适合皮肤再生，可以用作一次性移植程序治疗皮肤缺陷的皮肤模板。
