Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
Commun Biol. 2021 Jan 25;4(1):110. doi: 10.1038/s42003-020-01635-4.
Progress in bone scaffold development relies on cost-intensive and hardly scalable animal studies. In contrast to in vivo, in vitro studies are often conducted in the absence of dynamic compression. Here, we present an in vitro dynamic compression bioreactor approach to monitor bone formation in scaffolds under cyclic loading. A biopolymer was processed into mechanically competent bone scaffolds that incorporate a high-volume content of ultrasonically treated hydroxyapatite or a mixture with barium titanate nanoparticles. After seeding with human bone marrow stromal cells, time-lapsed imaging of scaffolds in bioreactors revealed increased bone formation in hydroxyapatite scaffolds under cyclic loading. This stimulatory effect was even more pronounced in scaffolds containing a mixture of barium titanate and hydroxyapatite and corroborated by immunohistological staining. Therefore, by combining mechanical loading and time-lapsed imaging, this in vitro bioreactor strategy may potentially accelerate development of engineered bone scaffolds and reduce the use of animals for experimentation.
骨支架开发的进展依赖于成本高昂且难以规模化的动物研究。与体内研究相比，体外研究往往在缺乏动态压缩的情况下进行。在这里，我们提出了一种体外动态压缩生物反应器方法，以监测在循环加载下支架中的骨形成。将生物聚合物加工成具有高体积含量的超声处理羟基磷灰石或与钛酸钡纳米粒子混合的机械性能良好的骨支架。在与骨髓基质细胞接种后，在生物反应器中对支架进行延时成像显示，在循环加载下羟基磷灰石支架中的骨形成增加。在含有钛酸钡和羟基磷灰石混合物的支架中，这种刺激作用更为明显，并通过免疫组织化学染色得到证实。因此，通过结合机械加载和延时成像，这种体外生物反应器策略可能有潜力加速工程骨支架的开发，并减少动物实验的使用。
