Beumer G J, van Blitterswijk C A, Bakker D, Ponec M
Department of Dermatology, University Hospital, Leiden, The Netherlands.
Clin Mater. 1993;14(1):21-7. doi: 10.1016/0267-6605(93)90043-7.
A bilayered matrix, as an integral part of a cell seeded skin substitute for deep dermal skin injury, is described. The skin substitute has been given a dense top layer, to function as a substrate for keratinocyte culture, and a porous under layer for wound adhesion and to serve as a template for dermal regeneration. This porous under layer may be seeded with dermal fibroblasts for improvement of neodermis formation. The elastomeric hydrogel Polyactive¿, a biodegradable polyether/polyester block copolymer, has been selected as the top layer component and Polyactive or Poly-L-lactide (PLLA) as the constituents of the under layer; this to ensure that the matrix is degradable and fulfils certain mechanical requirements. Polyactive top layers were found to be highly permeable to water vapour (+/-30 g/m -2 h -1 kPa) -1 and to molecules up to 150 kD (human IgG). Tensile properties of the bilayered matrices were to a considerable extent dependent on top layer and under layer composition and thickness. Elasticity moduli were in the range of those previously reported for human skin. Varying the weight ratios of the soft/hard segments of the Polyactives and/or substituting PLLA for Polyactive as the under layer component, allows the modulation of the matrix to specific application site dependent demands.
本文描述了一种双层基质，它是用于治疗深层真皮皮肤损伤的细胞接种皮肤替代物的一个组成部分。该皮肤替代物有一个致密的顶层，用作角质形成细胞培养的基质，还有一个多孔的底层，用于伤口黏附并作为真皮再生的模板。这个多孔底层可以接种真皮成纤维细胞以促进新真皮的形成。弹性水凝胶Polyactive®，一种可生物降解的聚醚/聚酯嵌段共聚物，已被选作顶层成分，而Polyactive或聚-L-丙交酯（PLLA）作为底层成分；这样可确保基质可降解并满足某些机械要求。发现Polyactive顶层对水蒸气具有高渗透性（±30 g/m²·h⁻¹·kPa⁻¹），并且对分子量高达150 kD的分子（人IgG）也具有高渗透性。双层基质的拉伸性能在很大程度上取决于顶层和底层的组成及厚度。弹性模量在先前报道的人体皮肤弹性模量范围内。改变Polyactives软/硬链段的重量比和/或用PLLA替代Polyactive作为底层成分，可以根据特定应用部位的需求对基质进行调节。
