Center for Scientific Instrumentation, Korea Basic Science Institute, Daejeon 34133, Republic of Korea.
Program in Biomicro System Technology, Korea University, Seoul 02841, Republic of Korea.
Biofabrication. 2024 Feb 29;16(2). doi: 10.1088/1758-5090/ad2a7e.
Versatile and efficient regulation of the mechanical properties of the extracellular matrix is crucial not only for understanding the dynamic changes in biological systems, but also for obtaining precise and effective cellular responses in drug testing. In this study, we developed a well plate-based hydrogel photo-crosslinking system to effectively control the mechanical properties of hydrogels and perform high-throughput assays. We improved cell biocompatibility by using gelatin methacryloyl (GelMA) with a visible light photo-crosslinking method. Multiple cell-laden GelMA hydrogels were simultaneously and uniformly created using multi-arrayed 520 nm light-emitting diodes in a well plate format. The elastic modulus of the hydrogels can be widely adjusted (0.5-30 kPa) using a photo-crosslinking system capable of independently controlling the light intensity or exposure time for multiple samples. We demonstrate the feasibility of our system by observing enhanced bone differentiation of human mesenchymal stem cells (hMSCs) cultured on stiffer hydrogels. Additionally, we observed that the osteogenic fate of hMSCs, affected by the different mechanical properties of the gel, was regulated by parathyroid hormone (PTH). Notably, in response to PTH, hMSCs in a high-stiffness microenvironment upregulate osteogenic differentiation while exhibiting increased proliferation in a low-stiffness microenvironment. Overall, the developed system enables the generation of multiple cell-laden three-dimensional cell culture models with diverse mechanical properties and holds significant potential for expansion into drug testing.
多功能且高效地调节细胞外基质的机械性能不仅对于理解生物系统的动态变化至关重要，而且对于在药物测试中获得精确且有效的细胞响应也至关重要。在本研究中，我们开发了一种基于微孔板的水凝胶光交联系统，可有效控制水凝胶的机械性能并进行高通量测定。我们使用明胶甲基丙烯酰（GelMA）和可见光光交联方法提高了细胞生物相容性。通过在微孔板格式中使用多阵列 520nm 发光二极管，同时且均匀地创建了多个含有细胞的 GelMA 水凝胶。使用能够独立控制多个样品的光强度或曝光时间的光交联系统，可广泛调节水凝胶的弹性模量（0.5-30kPa）。我们通过观察在较硬水凝胶上培养的人间充质干细胞（hMSCs）增强的骨分化来证明我们系统的可行性。此外，我们观察到凝胶的不同机械性能会影响 hMSCs 的成骨命运，甲状旁腺激素（PTH）会对此进行调节。值得注意的是，在高刚度微环境中，响应 PTH 的 hMSCs 上调成骨分化，而在低刚度微环境中则表现出增殖增加。总体而言，所开发的系统能够生成具有多种机械性能的多种细胞负载的三维细胞培养模型，并且具有扩展到药物测试的巨大潜力。
