Progress on bone regeneration therapy

UK scientists are working on a new, more effective method of hard tissue regeneration.

Dr Sophie Cox of the University of Birmingham, and colleagues, explain that each of the standard clinical approaches to stimulating or enhancing bone regeneration suffer from significant limitations.

"Even promising osteoinductive approaches utilising the growth factor BMP-2 have been subject to controversy and serious negative outcomes," they wrote in Scientific Reports yesterday (3 October).

So the team looked into a new method involving extra-cellular vesicles in combination with phosphate therapy. They describe this as "a significant departure from currently available therapeutic approaches, with the potential to help repair bone, teeth and cartilage".

Dr Cox says: "Extracellular vesicles harness the advantages of cell-based therapies but with less concern about immunological risks. Though we can never fully mimic the complexity of vesicles produced by cells in nature, this work describes a new pathway harnessing natural developmental processes to facilitate hard tissue repair."

The team tested the capacity of extracellular vesicles derived from mineralising osteoblasts. The vesicles were able to induce bone regeneration in mesenchymal stem cell cultures, outperforming the BMP-2 approach in terms of rate and volume of mineral deposition.

"Intriguingly, these effects were only observed in the presence of an exogenous phosphate source," they report. "These findings support the role of extracellular vesicles as early sites of mineral nucleation and demonstrate their value for promoting hard tissue regeneration."

First author, Dr Owen Davies, said: "It is early days, but the potential is there for this to transform the way we approach tissue repair. We’re now looking to produce these therapeutically valuable particles at scale and also examine their capacity to regenerate other tissues."

Davies, O. G. et al. Annexin-enriched osteoblast-derived vesicles act as an extracellular site of mineral nucleation within developing stem cell cultures. Scientific Reports 3 October 2017; doi: 10.1038/s41598-017-13027-6 [abstract]