Metformin as a protective supplement enhances survival and stemness maintenance of human dental pulp stem cells during cryopreservation

Abstract

This study explored the protective effects of metformin on human dental pulp stem cells (hDPSCs) during cryopreservation. hDPSCs were isolated from extracted third molars and treated with varying concentrations of metformin to identify the optimal dose for cryoprotection. Among the tested concentrations, 800 μM was found to effectively reduce reactive oxygen species without compromising cell viability. When used during cryopreservation, metformin significantly improved post-thaw survival, enhanced cell proliferation, and increased colony-forming efficiency. Importantly, it also upregulated key stemness-related genes, including OCT4, NANOG, SOX2, and KLF4. Even under repeated freeze-thaw stress, metformin mitigated functional decline, helping to preserve both cell viability and stem cell characteristics. These findings highlight metformin's potential as a protective supplement to enhance the preservation and clinical utility of hDPSCs.