Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas, USA.
Department of Plastic Surgery, University of Kansas Medical Center, Kansas City, Kansas, USA.
Wound Repair Regen. 2023 May-Jun;31(3):367-383. doi: 10.1111/wrr.13076. Epub 2023 Mar 21.
Mesenchymal stem/stromal cells (MSCs) are a heterogenous population of multipotent and highly secretory cells currently being investigated in the field of wound healing for their ability to augment tissue responses. The adaptive response of MSC populations to the rigid substrate of current 2D culture systems has been considered to result in a deterioration of regenerative 'stem-like' properties. In this study, we characterise how the improved culture of adipose-derived mesenchymal stem cells (ASCs) within a tissue-mimetic 3D hydrogel system, that is mechanically similar to native adipose tissue, enhances their regenerative capabilities. Notably, the hydrogel system contains a porous microarchitecture that permits mass transport, enabling efficient collection of secreted cellular compounds. By utilising this 3D system, ASCs retained a significantly higher expression of ASC 'stem-like' markers while demonstrating a significant reduction in senescent populations, relative to 2D. Additionally, culture of ASCs within the 3D system resulted in enhanced secretory activity with significant increases in the secretion of proteinaceous factors, antioxidants and extracellular vesicles (EVs) within the conditioned media (CM) fraction. Lastly, treatment of wound healing cells, keratinocytes (KCs) and fibroblasts (FBs), with ASC-CM from the 2D and 3D systems resulted in augmented functional regenerative activity, with ASC-CM from the 3D system significantly increasing KC and FB metabolic, proliferative and migratory activity. This study demonstrates the potential beneficial role of MSC culture within a tissue-mimetic 3D hydrogel system that more closely mimics native tissue mechanics, and subsequently how the improved phenotype augments secretory activity and potential wound healing capabilities of the MSC secretome.
间充质干细胞（MSCs）是一种异质性的多能和高分泌细胞群体，目前在伤口愈合领域因其增强组织反应的能力而受到研究。MSC 群体对当前 2D 培养系统刚性基质的适应性反应被认为导致再生“干细胞样”特性的恶化。在这项研究中，我们描述了如何通过在组织模拟 3D 水凝胶系统中更好地培养脂肪来源的间充质干细胞（ASCs），该系统在机械上类似于天然脂肪组织，从而增强其再生能力。值得注意的是，水凝胶系统具有允许质量传递的多孔微结构，能够有效地收集分泌的细胞化合物。通过利用这个 3D 系统，与 2D 相比，ASCs 保持了更高的 ASC“干细胞样”标志物表达，同时显著减少了衰老群体。此外，在 3D 系统中培养 ASC 导致分泌活性增强，条件培养基（CM）部分中蛋白质因子、抗氧化剂和细胞外囊泡（EVs）的分泌显著增加。最后，用来自 2D 和 3D 系统的 ASC-CM 处理伤口愈合细胞角质形成细胞（KC）和成纤维细胞（FB），导致功能再生活性增强，来自 3D 系统的 ASC-CM 显著增加 KC 和 FB 的代谢、增殖和迁移活性。这项研究表明，在更接近天然组织力学的组织模拟 3D 水凝胶系统中培养 MSC 的潜在有益作用，以及随后改善的表型如何增强 MSC 分泌组的分泌活性和潜在的伤口愈合能力。
