The potential of exosomes in the therapy of the cartilage and bone complications; emphasis on osteoarthritis.

Osteoarthritis is a prevalent worldwide joint disease, which demonstrates a remarkable adverse effect on the patients' life modality. Medicinal agents, exclusively nonsteroidal anti-inflammatory drugs (NSAIDs), have been routinely applied in the clinic. But, their effects are restricted to pain control with insignificant effects on cartilage renovation, which would finally lead to cartilage destruction. In the field of regenerative medicine, many researchers have tried to use stem cells to repair tissues and other human organs. However, in recent years, with the discovery of extracellular microvesicles, especially exosomes, researchers have been able to offer more exciting alternatives on the subject. Exosomes and microvesicles are derived from different types of bone cells such as mesenchymal stem cells, osteoblasts, and osteoclasts. They are also recognized to play substantial roles in bone remodeling processes including osteogenesis, osteoclastogenesis, and angiogenesis. Specifically, exosomes derived from a mesenchymal stem cell have shown a great potential for the desired purpose. Exosomal products include miRNA, DNA, proteins, and other factors. At present, if it is possible to extract exosomes from various stem cells effectively and load certain products or drugs into them, they can be used in diseases, such as rheumatoid arthritis, osteoarthritis, bone fractures, and other diseases. Of course, to achieve proper clinical use, advances have to be made to establish a promising regenerative ability for microvesicles for treatment purposes in the orthopedic disorders. In this review, we describe the exosomes biogenesis and bone cell derived exosomes in the regenerate process of bone and cartilage remodeling.