Biochemical and biomechanical gradients for directed bone marrow stromal cell differentiation toward tendon and bone
Biochemical and biomechanical gradients for directed bone marrow stromal cell differentiation toward tendon and bone
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DOI：
10.1016/j.biomaterials.2010.06.046
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发表时间：
2010-10-01
期刊：
影响因子：
14
通讯作者：
Snedeker, Jess G.
中科院分区：
文献类型：
--
作者：
Sharma, Ram I.;Snedeker, Jess G.
具有机械性能梯度和各种细胞外基质配体负载的底物被评估其指导骨髓基质细胞沿成骨和成腱谱系分化的能力。在验证了商业水凝胶梯度底物可重复的机械顺应特性后，底物被全长纤维连接蛋白或胶原功能化，这两种物质都存在于骨骼结构中，并且与细胞-基质信号传导有关。将骨髓基质细胞接种到生长培养基中的基质上，首先培养观察细胞的附着和形态，发现1 h后在胶原基质上的附着水平较高，24 h后扩散和组织趋势增加。分化研究表明，在纤维连接蛋白基质上成骨细胞分化增加，而胶原基质缺乏成骨分化。在较低硬度和较低配体密度的基质上，成骨分化减弱。分子研究揭示了成骨细胞相关信号分子的增加，这与分化研究一致，但在狭窄的硬度范围内检测到胶原基质上存在成腱细胞标记物。我们的研究结果表明，机械变异底物确实有望通过改变相关信号分子的基因水平表达，作为肌腱和骨定向分化的培养平台。这项研究有助于理解驱动基于底物的线索分化的分子机制，并有助于设计从肌腱到骨过渡的治疗性生物材料。(C) 2010 Elsevier Ltd.版权所有。
Substrates with mechanical property gradients and various extracellular matrix ligand loadings were evaluated for their ability to direct bone marrow stromal cell differentiation along osteogenic and tenogenic lineages. After verifying reproducible mechanical compliance characteristics of commercial hydrogel gradient substrates, substrates were functionalized with whole length fibronectin or collagen, both of which are found in skeletal structures and are relevant to cell-matrix signalling. Bone marrow stromal cells were seeded onto the substrates in growth media and cultured first to examine cell attachment and morphology, indicating higher levels of attachment on collagen substrates after 1 h, and increased spreading and organization trends after 24 h. Differentiation studies showed an increase in osteoblast differentiation on fibronectin substrates while collagen substrates lacked osteogenic differentiation. Osteogenic differentiation decreased on substrates of lower stiffness and lower ligand density. Molecular investigations revealed an increase in relevant signalling molecules for osteoblasts that were consistent with differentiation studies, but detected the presence of tenoblast markers on collagen substrates within a narrow range of stiffness. Our results indicate that mechanovariant substrates do hold promise as a culture platform for directed differentiation to tendon and bone by altering gene level expression of relevant signalling molecules. This study aids in understanding the molecular mechanisms that drive differentiation from substrate based cues, and could aid the design of therapeutic biomaterials at the transition from tendon to bone. (C) 2010 Elsevier Ltd. All rights reserved.