Regeneration of cartilage defects using engineered extracellular vesicles

In recent years, the number of adults with diagnosed cartilage defects has increased significantly, and various modes of treatment have been sought. However, traditional cartilage repair strategies have been proven inefficient, with limited success. Recently, regenerative treatment options have become more routinely used for specific indications, but they still have major limitations. Cell-derived extracellular vesicles (EVs) are becoming increasingly attractive for regenerative purposes because they provide several regenerative factors. In addition, they can be engineered to function as delivery agents for proteins, nucleic acids, and other molecules. Recently, EVs were explored for cartilage tissue engineering, with varying results. Unlike other cell-based therapies, this approach will lead to the avoidance of problems associated with immunogenic reactions against allogenic cells and easier approval of the therapy by regulatory bodies, which is expected to stimulate wider clinical application. Because of its broad interest and importance, this review was developed to discuss published works, their outcomes, and limitations and outline future research directions.