Time-lapsed imaging of nanocomposite scaffolds reveals increased bone formation in dynamic compression bioreactors

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. Schadli et al. present a bioreactor system that combines mechanical loading with longitudinal microCT imaging to assess bone mineralization in a poly(lactic-co-glycolic acid) (PLGA) scaffold reinforced with nanoparticles. This approach allows rapid and rigorous evaluation of engineered bone scaffolds performance in vitro and might reduce the use of animals for experimentation.

Automated summary

The research introduces an in vitro bioreactor approach combining mechanical loading and time-lapsed imaging to monitor bone formation in scaffolds, potentially accelerating the development of engineered bone scaffolds and reducing the use of animals for experimentation.