In vitro localization of bone growth factors in constructs of biodegradable scaffolds seeded with marrow stromal cells and cultured in a flow perfusion bioreactor
In vitro localization of bone growth factors in constructs of biodegradable scaffolds seeded with marrow stromal cells and cultured in a flow perfusion bioreactor
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DOI：
10.1089/ten.2006.12.177
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发表时间：
2006-01-01
影响因子：
--
通讯作者：
Mikos, AG
中科院分区：
文献类型：
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作者：
Gomes, ME;Bossano, CM;Mikos, AG
组织工程策略旨在控制单个细胞的行为来刺激组织形成。这种控制是通过模仿管理自然组织发育或修复的信号来实现的。流动灌注生物反应器可以创造具有最小扩散限制的培养环境，并为细胞提供机械刺激，这与体内骨形成的条件非常相似。因此，这些培养系统与合适的支架和细胞类型相结合，可能为体外组织工程模型的发展提供重要的见解，从而改进骨组织替代品的构建策略。本研究的目的是通过将大鼠骨髓基质细胞植入淀粉基可生物降解纤维网，在流动灌注生物反应器中培养大鼠骨髓基质细胞，研究几种通常与体内骨形成相关的骨生长因子的体外定位。使用免疫组织化学技术，在灌注条件下以两种不同流速培养的支架中，测定了几种骨相关生长因子（即转化生长因子- β 1、血小板衍生生长因子- a、成纤维细胞生长因子-2、血管内皮生长因子和骨形态发生蛋白-2）在两个不同时间点的定位。结果显示，除了血小板来源的生长因子- a外，所有考虑的生长因子都有阳性染色区域。此外，从阳性染色切片获得的图像表明，在较高的流速和培养时间下，免疫组织化学染色面积增加。这些观察结果表明，流动灌注增强了体外培养的支架/细胞结构的功能，因为它结合了生物和机械因素来增强结构内的细胞分化和细胞组织。本研究还表明，骨髓基质细胞的流动灌注生物反应器培养，结合适当的可生物降解纤维网的使用，可能构成体外研究骨形成和评估骨组织工程策略的有用模型。
Tissue engineering strategies aim at controlling the behavior of individual cells to stimulate tissue formation. This control is achieved by mimicking signals that manage natural tissue development or repair. Flow perfusion bioreactors that create culture environments with minimal diffusion constraints and provide cells with mechanical stimulation may closely resemble in vivo conditions for bone formation. Therefore, these culturing systems, in conjunction with an appropriate scaffold and cell type, may provide significant insight towards the development of in vitro tissue engineering models leading to improved strategies for the construction of bone tissue substitutes. The objective of this study was to investigate the in vitro localization of several bone growth factors that are usually associated with bone formation in vivo by culturing rat bone marrow stromal cells seeded onto starch-based biodegradable fiber meshes in a flow perfusion bioreactor. The localization of several bone-related growth factors-namely, transforming growth factor-beta 1, platelet-derived growth factor-A, fibroblast growth factor-2, vascular endothelial growth factor, and bone morphogenetic protein-2-was determined at two different time points in scaffolds cultured under perfusion conditions at two different flow rates using an immunohistochemistry technique. The results show the presence of regions positively stained for all the growth factors considered, except platelet-derived growth factor-A. Furthermore, the images obtained from the positively stained sections suggest an increase in the immunohistochemically stained area at the higher flow rate and culture time. These observations demonstrate that flow perfusion augments the functionality of scaffold/cell constructs grown in vitro as it combines both biological and mechanical factors to enhance cell differentiation and cell organization within the construct. This study also shows that flow perfusion bioreactor culture of marrow stromal cells, combined with the use of appropriate biodegradable fiber meshes, may constitute a useful model to study bone formation and assess bone tissue engineering strategies in vitro.