Regenerative medicine and tissue engineering potential of mesenchymal stem cells exosomes-derived microRNAs.

Mesenchymal stem cells (MSCs) have been revealed as an appropriate candidate for cell-based therapies by isolation from a different range of sources such as bone marrow, umbilical cord, adipose, liver, and orofacial tissues. MSCs showed low immunogenicity, which is considered as a potential alternative therapy for autoimmune and inflammatory diseases. Transplantation of MSCs in different research studies showed that it improves the repairment and regeneration of injured and impaired tissues. MSCs release biologically active molecules, such as extracellular vehicles (EVs) and exosomes (EXOs). EXOs participate in different physiological processes, including immune response, wound healing, bone repair, stem cell maintenance, interaction between the central nervous system (CNS), and pathological impacts in tumorigenesis, inflammation, and heart diseases. Across the tissues, MSCs release exosomes and regenerative molecules and transfer proteins, mRNAs and microRNAs. MicroRNAs (miRNAs) are small noncoding RNAs (21-23 nt) in length that bind to the 3' untranslated region (3'UTR) of target mRNA and post-transcriptionally regulate gene expression that affects different cellular pathways. More studies are needed relating to the exosome's biogenesis, cellular uptake, trafficking, isolation, qualification, purity, optimization, standardization, and molecular mechanisms of exosome connection with target cells. Recent studies reported promising applications of exosomes derived from various sources in regenerative medicine and tissue engineering approaches. Herein, we are more focused on studies with different approaches in regenerative medicine for tissue repair and healing related to bone, cartilage, tendon-bone, heart, nerves, wounds, skin, and tooth regeneration.