Researchers at University of Birmingham have recently developed an exciting new method for growing bone tissue ‘in a dish’. The developed bone resembled its natural counterpart on both a structural and functional level and could be used for studying many bone-related health issues.
While multiple studies have been released showing development of ‘bone-like’ structures in a lab, none have replicated the complex structure of bone to this extent. It, therefore, represents an interesting step forward in the field of orthopaedic research.
How It Works
In a multi-institute study, scientists in Prof. Liam Grover’s research group created an environment structurally similar to bone tissue at a critical stage of repair, namely a fracture callus.
Bone cells (periosteal cells - key cells in fracture healing) were grown/cultured over a 1-year period. However, the technique used to culture the cells was very specifically designed.
The periosteal cells were cultured within a network of materials designed to resemble the building blocks of a fracture callus. This specifically tailored environment gives the cells a perfect platform on which to carry out their normal function of kick-starting growth of new, healthy bone.
What is remarkable is the extent to which the periosteal cells developed. Over the 1 year period, researchers observed a transition into an entirely new cell type, namely an osteocyte.
This highly significant finding was perfectly summed up when I contacted Prof. Grover about his thoughts on the study.
“Osteocytes are the most numerous cells in bone, but are very difficult to maintain in culture. People can only really manage to culture them for around two weeks. What we did here, was to create a culture system where we were able to maintain this mature bone cell type for upwards of a year.”
As a result of the long term maintenance of the osteocytes and their interactions with the ‘callus-like’ surroundings, the researchers also observed a shift in the composition of the cell culture environment. The initial material network was slowly remodelled by the cells and eventually replaced with a cell-synthesised structure comprised of natural components found in bone.
As Prof. Grover recalls,
“Even more impressively, the cells themselves seemed to be linked by an intricate network of mineral tubes, like those that are found in real bone.”
Due to the close resemblance of the lab-grown structure to mature bone, there is potential to apply this model to studying bone formation in many different scenarios.
The published study includes data showing how the model can be used to study the effects of drugs targeted at limiting new bone formation. This is of particular interest in cases of severe bone trauma where bone can often form in soft tissue (known as heterotopic ossification), leading to multiple complications.
Additionally, there is scope to use such a platform to screen agents for promoting new bone formation and gaining a better understanding of how bone tissue is synthesised and organised into the complex structure that protects and supports the function of soft tissues within our body.
Ultimately, studies such as this bring the breakthroughs scientists make in the lab one step closer to the clinic.
The research was funded by a National Centre for the Replacement Refinement and Reduction of animals in research grant.
A. Iordachescu, H. D. Amin, S. M. Rankin, R. L. Williams, C. Yapp, A. Bannerman, A. Pacureanu, O. Addison, P. A. Hulley, L. M. Grover An In Vitro Model for the Development of Mature Bone Containing an Osteocyte Network Adv. Biosys. 2017, 1700156. https://doi.org/10.1002/adbi.201700156
Author: Sam Moxon; Biomaterials Research Associate at the University of Manchester Image: Courtesy A. Iordachescu, et al.