Extracellular matrix deposition and scaffold biodegradation in an in vitro three-dimensional model of bone by X-ray...

The development of an in vitro model of bone and the optimization of tools for determining the biological processes occurring during bone repair remains a major goal in the field of bone tissue engineering. Recently, a model based on a three-dimensional co-culture of osteoblasts and osteoclast precursors in Skelite(TM) scaffolds was developed. Although induction of osteoblast and osteoclast differentiation was observed, a complete evaluation of bone deposition and biodegradation processes was missing due to technical limitations. In the current study, both X-ray computed microtomography and histological analysis were used to monitor these two key biological processes in the same in vitro model. Either osteoblasts or a combination of osteoblasts and osteoclasts were seeded on Skelite(TM) scaffolds. Scaffold biodegradation and increased bone deposition together with a more organized extracellular matrix were observed in the co-cultures, highlighting the role of osteoclasts in the determination and regulation of bone deposition. Results confirmed the potential and relevance of co-culturing osteoblasts and osteoclasts to resemble native tissue. The combination of X-ray computed microtomography and histology presented in this study could be useful in future studies for the validation and development of new in vitro culture systems for bone tissue engineering.