Exosomes derived from human dental stem cell enhance the viability of odontoblasts

The purpose of this study was to assess the effects of exosomes derived from dental pulp mesenchymal stem cells (DPSCs) on the viability of odontoblast cells. Exosomes were extracted from human DPSC cells via ultracentrifugation. Scanning electron microscopy and western blot analysis for CD9 and CD81 demonstrated characteristics of exosomes. Developing odontoblasts were exposed to increasing concentrations of exosomes (10-400 ng/ml) over time periods of 24, 48, 72, and 96 hours. Cell viability was evaluated using MTT assays. In addition, real-time PCR was used to assess expression levels of Wnt, beta-catenin, PI3K, Akt, Bcl-2, and Bax in cells after 24-96 hours of exposure to 100 and 400 ng/ml exosomes. Odontoblast viability was found to be enhanced by DPSC-derived exosomes, with greater impacts at higher concentrations and time periods of 72-96 hours. Expression of PI3K, AKT, Wnt, beta-catenin, and Bcl-2 were notably upregulated in odontoblasts following 96 hours of DPSC-exosome treatment. Conversely, Bax expression was significantly downregulated. These findings suggest DPSC-exosomes promote odontoblast survival through modulated expression of genes involved in key survival pathways over extended exposure periods. Our findings demonstrated that exosomes derived from DPSC cells possess innate nanoparticle properties, leading to enhanced survival of odontoblast cells. This effect is achieved through the activation of the Wnt/beta-catenin and P3K/AKT signaling pathways, ultimately resulting in an increased Bcl-2/Bax ratio.