Calcium phosphate nanoparticles carrying YAP plasmid promote osteogenic potential in dental pulp stem cells by modulating BMP-2 expression and macrophage M2-like phenotype

PURPOSE: YAP is a well-established regulator of both osteogenic differentiation and macrophage polarization; however, conventional transfection reagents such as Lipofectamine are limited by inherent cytotoxicity. Herein, we investigated the efficacy of PEI-modified calcium phosphate nanoparticles (CaP/PEI-YAP) in enhancing DPSC osteogenic potential and elucidated the underlying macrophage-mediated mechanisms. MATERIALS AND METHODS: We synthesized and characterized CaP/PEI-YAP by XRD, FTIR, TEM, and particle size potentiostat, followed by assessing their uptake efficiency and cytotoxicity in DPSCs. The effect of CaP/PEI-YAP on osteoblastic differentiation and migration of DPSCs were evaluated. Extracellular calcium deposition was examined by Alizarin Red staining. Besides, we explored the impact of CaP/PEI-YAP on macrophage polarization. RESULTS: CaP/PEI-YAP could be taken up by DPSCs and exhibited lower cytotoxicity compared to lipofectamine 2000. DPSCs viability was decreased when exposed to the synthesized CaP/PEI-YAP (100 μg/mL). Compared with the CaP/PEI without YAP expression plasmid, cell migration of DPSCs in the CaP/PEI-YAP group was significantly elevated at 24 and 48 h, as demonstrated by wound healing and transwell assays. Increases of ALP activity and Alizarin red staining intensity indicated that DPSCs had differentiated toward an osteogenic lineage and showed extracellular calcium deposition after uptake of CaP/PEI-YAP by DPSCs. CaP/PEI-YAP promoted macrophage M2-like phenotype with increased Arg-1 and BMP-2 while decreased iNOS expression. CONCLUSION: CaP/PEI-YAP constitute an innovative and promising instrument for targeted dental pulp regeneration, with mechanisms potentially involving the osteogenic potential of DPSCs and polarization of macrophages M2-like phenotype.