The aim of EVERBONE was to develop and commercialise a new extracellular vesicle based multitargeted medicinal product for bone regeneration that mimics the beneficial effects of physical exercise, by recruiting endogenous cells to promote angiogenesis, osteogenesis and bone formation.
To achieve this, we initially designed a bioreactor setup that would enable the mechanical stimulation of cells and simultaneous collection of large quantities of conditioned media at scale. Utilising bioreactors, we then optimised the mechanical conditioning regime for osteocytes in terms of applied fluid flow induced shear stress to ensure the regenerative potential of secreted extracellular vesicles into the conditioned media was maximised. Interestingly, low magnitude shear stress generated the most regenerative EVs as determined by marrow stromal cell (MSC) osteogenesis. Similarly, angiogenesis was also enhanced by osteocyte derived EVs under low shear. Therefore, we next utilised these EVs as a systemic treatment to enhance regeneration of drill hole defect in the tibia of mouse. This analysis is currently ongoing but preliminary findings indicate a minimal influence of mineralised bone regeneration. Further analysis is ongoing to ascertain influence of EVs on angiogenesis and early callus formation.
Therefore, this project has identified and optimised the generation of regenerative EVs in vitro which have potential in vivo, although further analysis is required. The societal benefit of successfully realizing the potential of mechanically activated osteocyte derived EVs will be the development of an anabolic treatment for osteoporosis and bone repair that would reduce fracture risk and minimize hospital times, enabling the patient to regain independence in a timely manner.
