Max Bergmann Center of Biomaterials, Technische Universität Dresden, Budapester Straße 27, 01069 Dresden, Germany.
Biomaterials. 2012 Dec;33(35):8975-85. doi: 10.1016/j.biomaterials.2012.08.056. Epub 2012 Sep 17.
In vivo, bone formation is a complex, tightly regulated process, influenced by multiple biochemical and physical factors. To develop a vital bone tissue engineering construct, all of these individual components have to be considered and integrated to gain an in vivo-like stimulation of target cells. The purpose of the present studies was to investigate the synergistic role of defined biochemical and physical microenvironments with respect to osteogenic differentiation of human mesenchymal stem cells (MSCs). Biochemical microenvironments have been designed using artificial extracellular matrices (aECMs), containing collagen I (coll) and glycosaminoglycans (GAGs) like chondroitin sulfate (CS), or a high-sulfated hyaluronan derivative (sHya), formulated as coatings on three-dimensional poly(caprolactone-co-lactide) (PCL) scaffolds. As part of the physical microenvironment, cells were exposed to pulsed electric fields via transformer-like coupling (TC). Results showed that aECM containing sHya enhanced osteogenic differentiation represented by increases in ALP activity and gene-expression (RT-qPCR) of several bone-related proteins (RUNX-2, ALP, OPN). Electric field stimulation alone did not influence cell proliferation, but osteogenic differentiation was enhanced if osteogenic supplements were provided, showing synergistic effects by the combination of sHya and electric fields. These results will improve the understanding of bone regeneration processes and support the development of effective tissue engineered bone constructs.
在体内，骨形成是一个复杂的、受到多种生化和物理因素严格调控的过程。为了开发出有生命力的骨组织工程构建体，所有这些单独的成分都必须被考虑并整合在一起，以获得类似于体内的对靶细胞的刺激。本研究的目的是探讨明确的生化和物理微环境与人间充质干细胞（MSCs）成骨分化的协同作用。使用人工细胞外基质（aECM）设计了生化微环境，其中包含胶原蛋白 I（coll）和糖胺聚糖（GAGs），如硫酸软骨素（CS）或高硫酸化透明质酸衍生物（sHya），作为涂覆在三维聚（己内酯-共-乳酸）（PCL）支架上的涂层。作为物理微环境的一部分，细胞通过变压器样耦合（TC）暴露于脉冲电场中。结果表明，含有 sHya 的 aECM 通过增加碱性磷酸酶（ALP）活性和几种与骨相关的蛋白（RUNX-2、ALP、OPN）的基因表达（RT-qPCR）来增强成骨分化。电场刺激本身不会影响细胞增殖，但如果提供成骨补充剂，成骨分化会增强，表明 sHya 和电场的组合具有协同作用。这些结果将提高对骨再生过程的理解，并支持有效组织工程骨构建体的开发。
