Danalache Marina, Gaa Lena Karin, Burgun Charline, Umrath Felix, Naros Andreas, Alexander Dorothea
Department of Orthopedic Surgery, University Hospital Tübingen, 72072 Tübingen, Germany.
Department of Oral and Maxillofacial Surgery, University Hospital Tübingen, 72076 Tübingen, Germany.
Bioengineering (Basel). 2024 Dec 17;11(12):1282. doi: 10.3390/bioengineering11121282.
Cell functionality, driven by remarkable plasticity, is strongly influenced by mechanical forces that regulate mesenchymal stem cell (MSC) fate. This study explores the biomechanical properties of jaw periosteal cells (JPCs) and induced mesenchymal stem cells (iMSCs) under different culture conditions. We cultured both JPCs and iMSCs (n = 3) under normoxic and hypoxic environments, with and without osteogenic differentiation, and on laminin- or gelatin-coated substrates. Using atomic force microscopy, we measured cellular elasticity and Young's modulus of calcium phosphate precipitates (CaPPs) formed under osteogenic conditions. Correlation analyses between cellular stiffness, quantity of CaPP deposition, and stiffness of formed CaPPs were evaluated. The results showed that iMSCs, despite their softer cellular consistency, tended to form CaPPs of higher elastic moduli than osteogenically differentiated JPCs. Particularly under normoxic conditions, JPCs formed stronger CaPPs with lower cellular stiffness profiles. Conversely, iMSCs cultivated under hypoxic conditions on laminin-coated surfaces produced stronger CaPPs while maintaining lower cellular stiffness. We conclude that JPCs and iMSCs display distinct biomechanical responses to culture conditions. While JPCs increase cellular stiffness during osteogenic differentiation, in particular under hypoxic conditions, iMSCs exhibit a decrease in stiffness, indicating a higher resistance to lower oxygen levels. In both cell types, a lower cellular stiffness profile correlates with enhanced mineralization, indicating that this biomechanical fingerprint serves as a critical marker for osteogenic differentiation.
细胞功能由显著的可塑性驱动，受到调节间充质干细胞（MSC）命运的机械力的强烈影响。本研究探讨了不同培养条件下颌骨骨膜细胞（JPCs）和诱导间充质干细胞（iMSCs）的生物力学特性。我们在常氧和低氧环境下，在有和没有成骨分化的情况下，以及在层粘连蛋白或明胶包被的基质上培养JPCs和iMSCs（n = 3）。使用原子力显微镜，我们测量了在成骨条件下形成的磷酸钙沉淀物（CaPPs）的细胞弹性和杨氏模量。评估了细胞硬度、CaPP沉积量和形成的CaPPs硬度之间的相关性分析。结果表明，iMSCs尽管细胞质地较软，但倾向于形成比成骨分化的JPCs具有更高弹性模量的CaPPs。特别是在常氧条件下，JPCs形成了更强的CaPPs，细胞硬度较低。相反，在低氧条件下在层粘连蛋白包被表面培养的iMSCs产生了更强的CaPPs，同时保持较低的细胞硬度。我们得出结论，JPCs和iMSCs对培养条件表现出不同的生物力学反应。虽然JPCs在成骨分化过程中增加细胞硬度，特别是在低氧条件下，但iMSCs表现出硬度降低，表明对较低氧水平具有更高的抗性。在两种细胞类型中，较低的细胞硬度与增强的矿化相关，表明这种生物力学特征是成骨分化的关键标志物。
