Gelatin-methacryloyl (GelMA) is a highly adaptable biomaterial extensively utilized in skin regeneration applications. However, it is frequently imperative to enhance its physical and biological qualities by including supplementary substances in its composition. The purpose of this study was to fabricate and characterize a bi-layered GelMA-gelatin scaffold using 3D bioprinting. The upper section of the scaffold was encompassed with keratinocytes to simulate the epidermis, while the lower section included fibroblasts and HUVEC cells to mimic the dermis. A further step involved the addition of amniotic membrane extract (AME) to the scaffold in order to promote angiogenesis. The incorporation of gelatin into GelMA was found to enhance its stability and mechanical qualities. While the Alamar blue test demonstrated that a high concentration of GelMA (20%) resulted in a decrease in cell viability, the live/dead cell staining revealed that incorporation of AME increased the quantity of viable HUVECs. Further, gelatin upregulated the expression of KRT10 in keratinocytes and VIM in fibroblasts. Additionally, the histological staining results demonstrated the formation of well-defined skin layers and the creation of extracellular matrix (ECM) in GelMA/gelatin hydrogels during a 14-day culture period. Our study showed that a 3D-bioprinted composite scaffold comprising GelMA, gelatin, and AME can be used to regenerate skin tissues.

明胶甲基丙烯酰 (GelMA) 是一种高度适应性的生物材料，广泛应用于皮肤再生应用。然而，通常必须通过在其成分中包含补充物质来增强其物理和生物品质。本研究的目的是使用 3D 生物打印技术制造双层 GelMA-明胶支架并对其进行表征。支架的上半部分被角质形成细胞包围以模拟表皮，而下半部分则包括成纤维细胞和 HUVEC 细胞以模拟真皮。进一步的步骤涉及向支架添加羊膜提取物（AME）以促进血管生成。研究发现，将明胶掺入 GelMA 可以增强其稳定性和机械品质。虽然阿拉玛蓝测试表明高浓度的 GelMA (20%) 会导致细胞活力下降，但活细胞/死细胞染色显示 AME 的掺入增加了存活 HUVEC 的数量。此外，明胶上调角质形成细胞中 KRT10 和成纤维细胞中 VIM 的表达。此外，组织学染色结果表明，在 14 天的培养期间，GelMA/明胶水凝胶中形成了清晰的皮肤层和细胞外基质 (ECM)。我们的研究表明，由 GelMA、明胶和 AME 组成的 3D 生物打印复合支架可用于再生皮肤组织。