Scallop mantle-derived exosomes promote osteoblast formation and alleviate osteoporosis in mice

Osteoporosis, the most prevalent metabolic bone disease, has emerged as a serious public health concern. Safe and effective therapeutic interventions for osteoporosis are urgently needed. Here, we demonstrated that scallop mantle-derived exosomes (SMEs) promoted osteogenesis and prevented osteoporosis in ovariectomy-induced osteoporotic mice. Specifically, we successfully isolated SMEs with typical exosome morphology and desirable particle size. SMEs were found to contain abundant functional lipids, metabolites, and osteogenic-related proteins. Cell experiments revealed that SMEs could be internalized by osteoblastic MC3T3-E1 cells and promoted the proliferation, differentiation, and mineralization of MC3T3-E1 cells. In addition, SMEs survived the hostile gastrointestinal conditions and accumulated in the bone of mice after oral administration. Further mice investigations demonstrated that orally administered SMEs efficiently alleviated the bone loss, and improved the bone microstructure and biochemical properties in an ovariectomy-induced osteoporosis mouse model. Overall, these results reveal the osteogenesis effect of dietary SMEs, suggesting the potential of SMEs as an alternative or adjunct therapeutic agent in preventing or ameliorating osteoporosis.