Research Progress on Mesenchymal Stem Cells-Derived Small Size Vesicles for the Treatment of Liver Diseases

Liver disease is a major public health challenge, accounting for a substantial burden of mortality and morbidity worldwide. Currently, liver transplantation is the gold standard for treating end-stage liver diseases. However, it is affected by the shortage of organ sources and immune rejection. Mesenchymal stem cells (MSCs) can be used as an alternative therapy for liver diseases, especially in cases of liver cirrhosis, liver failure and complications of liver transplantation. However, MSCs may have potential effects on tumor occurrence. MSCs derived small size vesicles are nanoscale extracellular vesicles (EVs) which secreted by MSCs. MSCs derived small size vesicles are characterized by a lipid bilayer membrane, which encapsulate and transport various biomolecules such as proteins and miRNAs. Compared to MSCs, MSCs derived small size vesicles showed more advantages including lower tumor occurrence and lower toxicity. It has been found that MSCs derived small size vesicles ameliorate liver diseases via regulating lipid metabolism, inhibiting apoptosis, promoting regeneration, suppressing inflammation, drug delivery and so on. Based on the important role of MSCs derived small size vesicles in liver diseases treatment, this review aims to summarize the biological processes of small size vesicles with focusing on the effect of MSCs derived small size vesicles on different liver diseases. Additionally, we also discussed the potential future directions for small size vesicles research, including the challenges to be overcome and the prospects for clinical applications. This review provides theoretical support of MSCs derived small size vesicles as a potential therapeutic agent for liver disease in humans.