The skin is a combination of two different types of tissue—epithelial and connective (mesenchymal). The outer protective layer of the skin, the epidermis, consists of multiple layers of keratinocytes residing on the basement membrane that separates them from the underlying dermis, which consists of a well-vascularized fibrous extracellular matrix seeded mainly by fibroblasts and mesenchymal stromal cells. These skin features suggest that the development of a fibroblast-friendly porous scaffold covered with a flat dense sheath mimicking the basement membrane, and sufficient to support keratinocyte attachment, would be a reasonable approach in the generation of clinically-relevant skin substitutes useful for reconstructive dermatology and burn treatment. Therefore, we developed a procedure to obtain biocompatible composite bilayer scaffolds comprising a spongy dermis-like body (supporting vascularization and appropriate fibroblast and multipotent stromal cell activity) fused with a film-like cover (supporting keratinocyte attachment, growth and differentiation). The sodium alginate (SA), an algae-derived biopolymer, has been used as a base component for these scaffolds while collagen (CL) and fibrinogen (FG) were used as minor additives in variable concentrations. The slow rates of composite SA-based scaffold biodegradation were achieved by using Ba²⁺ as cross-linking cations. By manipulating the SA/CL/FG ratio we managed to obtain sponge scaffolds with highly interconnected porous structures, with an average pore size ranging from 60 to 300 μm, and sufficient tensile strength (3.12–5.26 MPa). The scaffolds biocompatibility with the major human skin cell types was confirmed by seeding the scaffold sponge compartment with primary skin fibroblasts and subcutaneous adipose-derived stromal cells while the film side biocompatibility was tested using primary human keratinocytes. The obtained results have shown that bilayer alginate-based scaffolds have biological and mechanical properties comparable with CL scaffolds but surpass them in cost efficiency and vascularization ability in the subcutaneous implantation model in laboratory mice.

皮肤是两种不同类型组织的组合——上皮组织和结缔组织（间充质）。皮肤的外部保护层，即表皮，由位于基底膜上的多层角质形成细胞组成，将它们与下面的真皮隔开，真皮由主要由成纤维细胞和间充质基质细胞播种的血管化纤维状细胞外基质组成。这些皮肤特征表明，开发一种对成纤维细胞友好的多孔支架，其覆盖有一个模拟基底膜的扁平致密鞘，并足以支持角质形成细胞的附着，这将是产生可用于重建皮肤病学的临床相关皮肤替代物的合理方法和烧伤治疗。所以，我们开发了一种获得生物相容性复合双层支架的程序，该支架包括海绵状真皮体（支持血管化和适当的成纤维细胞和多能基质细胞活性）与薄膜状覆盖物（支持角质形成细胞附着、生长和分化）融合。海藻酸钠 (SA) 是一种藻类衍生的生物聚合物，已被用作这些支架的基础成分，而胶原蛋白 (CL) 和纤维蛋白原 (FG) 则被用作不同浓度的微量添加剂。通过使用 Ba 实现了复合 SA 基支架生物降解的缓慢速率 一种藻类衍生的生物聚合物已被用作这些支架的基础成分，而胶原蛋白 (CL) 和纤维蛋白原 (FG) 则被用作不同浓度的微量添加剂。通过使用 Ba 实现了复合 SA 基支架生物降解的缓慢速率 一种藻类衍生的生物聚合物已被用作这些支架的基础成分，而胶原蛋白 (CL) 和纤维蛋白原 (FG) 则被用作不同浓度的微量添加剂。通过使用 Ba 实现了复合 SA 基支架生物降解的缓慢速率²⁺作为交联阳离子。通过控制 SA/CL/FG 比率，我们设法获得了具有高度互连多孔结构的海绵支架，平均孔径范围为 60 至 300 μm，并且具有足够的拉伸强度（3.12-5.26 MPa）。支架与主要人类皮肤细胞类型的生物相容性通过在支架海绵隔室中接种原代皮肤成纤维细胞和皮下脂肪来源的基质细胞来确认，而使用原代人类角质形成细胞测试薄膜侧的生物相容性。所获得的结果表明，基于藻酸盐的双层支架具有与 CL 支架相当的生物学和机械性能，但在实验室小鼠皮下植入模型中的成本效率和血管化能力方面超过了它们。