Research progress of exosomes in orthopedics

Exosomes are nano-extracellular vesicles that cells secrete to communicate with each other. They carry proteins, genes, and other bioactive substances. These vesicles influence various cellular processes like proliferation, migration, and angiogenesis. Exosomes are relevant to many diseases, including orthopedic conditions. Exosomes derived from bone cells like mesenchymal stem cells, osteoblasts, and osteoclasts play key roles in bone remodeling. They influence osteogenesis (bone formation), osteoclastogenesis (bone resorption), and angiogenesis (blood vessel formation) within the bone. This review summarizes the characteristics of exosomes and their role in various orthopedic conditions. These conditions include bone remodeling, bone tumors, vascular skeletal muscle injury, spinal cord injury, degenerative disc diseases, cartilage degeneration, osteoarthritis, necrosis of the femoral head, and osteoporosis.

• 1
  Mesenchymal stem cell (MSC) exosomes participate in tissue repair and injury processes, suggesting their potential as drug carriers. Macrophage-derived exosomes can affect the tissue microenvironment by modulating immune function and tend to accumulate in cancer cells due to specific surface proteins.
• 2
  Exosomes secreted by bone marrow mesenchymal stem cells (BM-MSCs) can stimulate osteoblast differentiation. They contain highly enriched osteogenic miRNAs, like miR-196a, miR-27a, and miR-206, potentially involved in promoting bone regeneration.
• 3
  Exosomes have shown promise in treating glucocorticoid-induced femoral head necrosis by promoting the proliferation of BMSCs, osteoblasts, and vascular endothelial cells. They also promote osteogenic differentiation of BMSCs and angiogenesis, while resisting apoptosis caused by high glucocorticoid levels.