Hydrodynamic compression of young and adult rat osteoblast-like cells on titanium fiber mesh.
Hydrodynamic compression of young and adult rat osteoblast-like cells on titanium fiber mesh.
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DOI：
10.1002/jbm.a.30304
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
X. Walboomers;S. Elder;J. Bumgardner;J. Jansen
中科院分区：
文献类型：
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作者：
X. Walboomers;S. Elder;J. Bumgardner;J. Jansen
活骨细胞对机械负荷有反应。因此，已经开发了许多体外模型来检查负载对细胞的应用。然而，并不是所有的系统都适合于纤维和多孔的三维材料，这些材料更适合于组织修复目的，或者用于组织工程支架的生产。对于三维应用，必须考虑具有流体流动系统或流体动压系统的单元的机械载荷。在这里，我们旨在评估成骨细胞样细胞在三维钛纤维网状支架材料中生长时对水动力压缩的反应。为此，定制了一个流体动力压缩室。从幼年（12日龄）或老年（1岁）大鼠股骨中获得骨髓细胞，并在地塞米松和β -甘油磷酸酯存在下进行预培养，以获得成骨细胞样表型。随后，将细胞接种到钛网支架上，在1 Hz下交替施加0.3 - 5.0 MPa的动水压力，间隔15分钟，每天共60分钟，持续3天。加压后，检测细胞活力。随后，测定DNA水平、碱性磷酸酶（ALP）活性和细胞外钙含量。最后对所有标本进行扫描电镜观察。细胞活力研究表明，施加的压力对细胞无害。此外，我们发现细胞能够检测到压缩力，因为我们确实看到了来自老年动物的细胞对细胞数量的明显影响。然而，压力下的细胞没有其他变化。最后，同样值得注意的是，老年动物的细胞不表达ALP活性，但确实表现出与年轻动物细胞相似的钙化细胞外基质形成。总之，DNA水平对压力反应的差异和ALP水平的差异表明，骨髓来源的成骨细胞样细胞的成骨特性随供体年龄的不同而不同。
Living bone cells are responsive to mechanical loading. Consequently, numerous in vitro models have been developed to examine the application of loading to cells. However, not all systems are suitable for the fibrous and porous three-dimensional materials, which are preferable for tissue repair purposes, or for the production of tissue engineering scaffolds. For three-dimensional applications, mechanical loading of cells with either fluid flow systems or hydrodynamic pressure systems has to be considered. Here, we aimed to evaluate the response of osteoblast-like cells to hydrodynamic compression, while growing in a three-dimensional titanium fiber mesh scaffolding material. For this purpose, a custom hydrodynamic compression chamber was built. Bone marrow cells were obtained from the femora of young (12-day-old) or old (1-year-old) rats, and precultured in the presence of dexamethasone and beta-glycerophosphate to achieve an osteoblast-like phenotype. Subsequently, cells were seeded onto the titanium mesh scaffolds, and subjected to hydrodynamic pressure, alternating between 0.3 to 5.0 MPa at 1 Hz, at 15-min intervals for a total of 60 min per day for up to 3 days. After pressurization, cell viability was checked. Afterward, DNA levels, alkaline phosphatase (ALP) activity, and extracellular calcium content were measured. Finally, all specimens were observed with scanning electron microscopy. Cell viability studies showed that the applied pressure was not harmful to the cells. Furthermore, we found that cells were able to detect the compression forces, because we did see evident effects on the cell numbers of the cells derived from old animals. However, there were no other changes in the cells under pressure. Finally, it was also noticeable that cells from old animals did not express ALP activity, but did show similar calcified extracellular matrix formation to the cells from young animals. In conclusion, the difference in DNA levels as reaction toward pressure, and the difference in ALP levels, suggest that the osteogenic properties of bone marrow-derived osteoblast-like cells are different with respect to the age of the donor.