Engineered exosomes: A new promise for the management of musculoskeletal diseases.

BACKGROUND Exosomes are nanovesicles actively secreted by potentially all cell types, including tumour cells, with the primary role of extracellular systemic communication mediators, both at autocrine and paracrine levels, at short and long distances. Recently, different studies have used exosomes as a delivery system for a plethora of different molecules, such as drugs, microRNAs and proteins. This has been made possible thanks to the simplicity in exosomes engineering, their great stability and versatility for applications in oncology as well as in regenerative medicine. SCOPE OF REVIEW The aim of this review is to provide information on the state-of-the-art and possible applications of engineered exosomes, both for cargo and specific cell-targeting, in different pathologies related to the musculoskeletal system. MAJOR CONCLUSIONS The use of exosomes as therapeutic agents is rapidly evolving, different studies explore drug delivery with exosomes using different molecules, showing an enormous potential in various research fields such as oncology and regenerative medicine. GENERAL SIGNIFICANCE However, despite the significant progress made by the different studies carried out, currently, the use of exosomes is not a therapeutic reality for the considerable difficulties to overcome.