Abstract
OBJECTIVE: To explore the synergistic effect of nano-pearl powder (NPP) and adipose-derived stem cell exosomes (ADSC-Exos) on the osteogenic potential of MC3T3-E1 cells. METHODS: The water-soluble matrix of NPP (NPP-WSM) was extracted via freeze-drying, and ADSC-Exos were isolated by ultracentrifugation. NPP-WSM was incorporated into ADSC-Exos through co-incubation to generate NPP-WSM-Exos. MC3T3-E1 cells were treated with NPP-WSM or NPP-WSM-Exos. Cell proliferation and migration were evaluated using CCK-8 and wound-healing assays, respectively. Osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. The expression of osteogenesis-related genes (COL1A1, RUNX2, OCN, and OPN) was measured by qPCR and Western blotting. Transcriptome sequencing (RNA-seq) was conducted to identify signaling pathways activated by NPP-WSM-Exos. RESULTS: NPP-WSM-Exos displayed distinct exosome morphology and biomarkers, confirming their successful preparation. Significantly, NPP-WSM-Exos enhanced the viability of MC3T3-E1 cells compared to NPP-WSM alone and upregulated the expression of osteogenic genes, including COL1A1, RUNX2, OCN, and OPN, at both the transcriptional and translational levels. Additionally, NPP-WSM-Exos strongly promoted mineralization, as evidenced by the increased calcification observed through Alizarin Red S staining, and elevated alkaline phosphatase (ALP) activity, indicating excellent potential for osteogenic differentiation. Transcriptome sequencing showed that NPP-WSM-Exos significantly enhanced the PI3K/AKT pathway in MC3T3-E1 cells, while protein level detection indicated that NPP-WSM-Exos could increase AKT phosphorylation levels and inhibit GSK3β activity to improve osteogenic efficiency. CONCLUSION: The use of adipose-derived stem cell exosomes to encapsulate NPP-WSM can increase the utilization of WSM, promote the proliferation of MC3T3-E1, and enhance the osteogenic differentiation ability.