Crecente-Campo Jose, Borrajo Erea, Vidal Anxo, Garcia-Fuentes Marcos
Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidade de Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain.
Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidade de Santiago de Compostela, Avda. Barcelona s/n, 15782 Santiago de Compostela, Spain.
Eur J Pharm Biopharm. 2017 May;114:69-78. doi: 10.1016/j.ejpb.2016.12.021. Epub 2017 Jan 10.
The regeneration of articular cartilage remains an unresolved question despite the current access to a variety of tissue scaffolds activated with growth factors relevant to this application. Further advances might result from combining more than one of these factors; here, we propose a scaffold composition optimized for the dual delivery of BMP-7 and TGF-β3, two proteins with described chondrogenic activity. First, we tested in a mesenchymal stem cell micromass culture with TGF-β3 whether the exposure to microspheres loaded with BMP-7 would improve cartilage formation. Histology and qRT-PCR data confirmed that the sustained release of BMP-7 cooperates with TGF-β3 towards chondrogenic differentiation. Then, we optimized a scaffold prototype for tissue culture and dual encapsulation of BMP-7 and TGF-β3. The scaffolds were prepared from poly(lactic-co-glycolic acid), and BMP-7/TGF-β3 were loaded as nanocomplexes with heparin and Tetronic 1107. The scaffolds showed the sustained release of both proteins over four weeks, with minimal burst effect. We finally cultured human mesenchymal stem cells on these scaffolds, in the absence of exogenous chondrogenic factor supplementation. The cells cultured on the scaffolds loaded with BMP-7 and TGF-β3 showed clear signs of cartilage formation macroscopically and histologically. RT-PCR studies confirmed a clear upregulation of cartilage markers SOX9 and Aggrecan. In summary, scaffolds encapsulating BMP-7 and TGF-β3 can efficiently deliver a cooperative growth factor combination that drives efficient cartilage formation in human mesenchymal stem cell cultures. These results open attractive perspectives towards in vivo translation of this technology in cartilage regeneration experiments.
尽管目前有多种用与该应用相关的生长因子激活的组织支架，但关节软骨的再生仍然是一个未解决的问题。将多种此类因子结合起来可能会带来进一步的进展；在此，我们提出一种针对骨形态发生蛋白-7（BMP-7）和转化生长因子-β3（TGF-β3）这两种具有软骨生成活性的蛋白质的双重递送而优化的支架组合物。首先，我们在含有TGF-β3的间充质干细胞微团培养中测试了暴露于负载BMP-7的微球是否会改善软骨形成。组织学和定量逆转录聚合酶链反应（qRT-PCR）数据证实，BMP-7的持续释放与TGF-β3协同促进软骨生成分化。然后，我们优化了一种用于组织培养以及BMP-7和TGF-β3双重包封的支架原型。这些支架由聚乳酸-乙醇酸共聚物制备而成，BMP-7/TGF-β3作为与肝素和四臂聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物（Tetronic 1107）的纳米复合物载入。这些支架在四周内显示出两种蛋白质的持续释放，且爆发效应最小。我们最终在这些支架上培养人间充质干细胞，且不添加外源性软骨生成因子。在负载BMP-7和TGF-β3的支架上培养的细胞在宏观和组织学上均显示出明显的软骨形成迹象。逆转录聚合酶链反应（RT-PCR）研究证实软骨标志物SRY-box转录因子9（SOX9）和聚集蛋白聚糖明显上调。总之，包封BMP-7和TGF-β3的支架能够有效地递送协同生长因子组合，从而在人间充质干细胞培养中驱动高效的软骨形成。这些结果为该技术在软骨再生实验中的体内转化开辟了有吸引力的前景。
