Matrix bound nanovesicles: A great promise for TERM in less than a decade of research

Decellularized extracellular matrix materials have been widely studied for tissue engineering and regenerative medicine (TERM) applications, largely because of their intrinsic bioactivity and immunomodulatory potentials. These properties confer decellularized extracellular matrix biomaterials a biological advantage over other biomaterials, especially synthetic ones, leading to several successful applications in TERM. While the complex composition of decellularized materials is well known and thought to play a role in providing the regenerative advantage, the fine mechanisms laying behind their bioactivity and immunomodulation were not fully understood yet. In the last decade, researchers have discovered a novel component in decellularized extracellular matrix materials: the matrix bound nanovesicle (MBV). This newly described type of extracellular vesicle is characterized by a tight relation to the extracellular matrix, differently from other liquid phase vesicles, and presents a unique tissue specific cargo, thought to be secreted by cells for specific cell signalling purposes. Although other extracellular vesicles subtypes have been extensively studied in past years, MBVs are different in many ways, making this research field noticeably young. Major bioactivity and immune modulating ability are key features of MBVs that were evident right from the first research works. However, to understand how MBVs can recapitulate and confer decellularized biomaterials with their signature biological performance, they are being characterized in depth. In particular, their rich and varied cargo is being explored, which has shown to play a fundamental role in MBVs' biological potential. This discovery not only revolutionized the look on decellularized extracellular matrix materials, but it also opened the way for research on a novel type of biomaterial, with plenty potential in therapeutical and regenerative applications. This review presents in detail what has been discovered up to now on MBVs, their properties, biological roles, and potential in TERM.