Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
59th Medical Wing Science and Technology, JBSA-Lackland, TX 78236, USA.
Int J Mol Sci. 2024 May 3;25(9):4992. doi: 10.3390/ijms25094992.
One of the primary complications in generating physiologically representative skin tissue is the inability to integrate vasculature into the system, which has been shown to promote the proliferation of basal keratinocytes and consequent keratinocyte differentiation, and is necessary for mimicking representative barrier function in the skin and physiological transport properties. We created a 3D vascularized human skin equivalent (VHSE) with a dermal and epidermal layer, and compared keratinocyte differentiation (immunomarker staining), epidermal thickness (H&E staining), and barrier function (transepithelial electrical resistance (TEER) and dextran permeability) to a static, organotypic avascular HSE (AHSE). The VHSE had a significantly thicker epidermal layer and increased resistance, both an indication of increased barrier function, compared to the AHSE. The inclusion of keratin in our collagen hydrogel extracellular matrix (ECM) increased keratinocyte differentiation and barrier function, indicated by greater resistance and decreased permeability. Surprisingly, however, endothelial cells grown in a collagen/keratin extracellular environment showed increased cell growth and decreased vascular permeability, indicating a more confluent and tighter vessel compared to those grown in a pure collagen environment. The development of a novel VHSE, which incorporated physiological vasculature and a unique collagen/keratin ECM, improved barrier function, vessel development, and skin structure compared to a static AHSE model.
生成具有生理代表性的皮肤组织的主要并发症之一是无法将脉管系统整合到系统中，这已被证明可以促进基底角质形成细胞的增殖和随后的角质形成细胞分化，并且对于模拟皮肤的代表性屏障功能和生理转运特性是必要的。我们创建了具有真皮和表皮层的 3D 血管化人皮肤等效物 (VHSE)，并将角质形成细胞分化（免疫标志物染色）、表皮厚度（H&E 染色）和屏障功能（跨上皮电阻 (TEER) 和葡聚糖通透性）与静态、器官型无血管 HSE (AHSE) 进行了比较。与 AHSE 相比，VHSE 的表皮层明显更厚，电阻增加，这表明屏障功能增强。我们在胶原水凝胶细胞外基质 (ECM) 中加入角蛋白，增加了角质形成细胞的分化和屏障功能，表现为电阻增加和通透性降低。然而，令人惊讶的是，在胶原/角蛋白细胞外环境中生长的内皮细胞表现出更高的细胞生长和更低的血管通透性，表明与在纯胶原环境中生长的细胞相比，血管更密集和更紧密。与静态 AHSE 模型相比，新型 VHSE 的开发，其中包含了生理血管和独特的胶原/角蛋白 ECM，改善了屏障功能、血管发育和皮肤结构。
