Abstract
By combining cells, biological factors, and biomaterials the field of tissue engineering has generated technologies capable of supporting regeneration. However, the regulatory hurdles associated with the use of cell-based therapies often hinder translation. Consequently, to meet the growing demand for regenerative technologies new approaches are needed. Emerging evidence suggests that cell-derived extracellular vesicles (EVs) are critical in cell-cell communication and regulation of bone formation. This talk will explore the role of osteoblast EVs in directing stem-cell differentiation in-vitro. EVs were isolated from cell culture media by ultracentrifugation and profiled for size and composition using a range of techniques. Notably, proteomic analysis revealed the presence of calcium channelling annexins and bridging collagens that may be key to their role in mineralisation. To minimise the concentration of EVs required to induce a pro-osteogenic effect we propose that they may be locally delivered. Opportunities to incorporate these pro-osteogenic EVs into injectable biomaterials will be discussed, in particular the formulation of microcapsules and fluid-gels. In summary, incorporation of EVs in tissue-engineered scaffolds has the potential to deliver all the advantages of a cell-based therapy but without using viable cells. The advantages of this approach may represent a new phase of tissue engineering.
