Osteogenic Induction Activity of Magnesium Chloride on Human Periodontal Ligament Stem Cells

Periodontal ligament stem cells (PDLSCs) are promising for regenerative therapies due to their self-renewal and multilineage differentiation, essential for periodontal tissue repair. Although magnesium plays a vital role in bone metabolism, its specific effects on PDLSCs and potential applications in regeneration are unclear. This study aimed to investigate the effects of magnesium chloride (MgCl₂) on the proliferation and osteogenic differentiation of human PDLSCs (hPDLSCs).

hPDLSCs were isolated, characterised, and treated with 0.1-40 mM MgCl₂. Cell viability and proliferation were assessed using an MTT assay. Cell migration was measured by a scratch assay. Colony-forming unit formation and cell cycle analysis were examined using crystal violet and propidium iodide staining. Osteogenic differentiation was assessed through alkaline phosphatase activity, Alizarin Red S staining, and RT-qPCR for osteogenic-related gene expression. RNA sequencing was performed to evaluate differential gene expression patterns in hPDLSCs treated with 10 mM MgCl₂. All statistical analyses were evaluated at P < .05.

hPDLSCs exhibited mesenchymal stem cell characteristics. MgCl₂ concentrations higher than 10 mM were cytotoxic. Significant increases in cell proliferation, colony-forming unit percentages, and active cell cycle activity were observed when treated with 0.1, 0.5, and 1 mM MgCl₂. However, MgCl₂ had no effect on cell migration. Mineralised nodule formation was observed in hPDLSCs treated with 0.1 and 0.5 mM MgCl₂ in osteogenic induction media, mediated by TRPM7 cation channel, along with upregulated expression of osteogenic marker genes. Bioinformatic analysis indicated alterations in chemokine signalling and cellular calcium homeostasis pathways when treated with 10 mM MgCl₂.

MgCl₂ at a dose of 0.1 mM is the most effective concentration to promote cell proliferation and stimulate osteogenic differentiation of hPDLSCs in vitro. These findings indicate that MgCl₂ enhances both the proliferation and osteogenic differentiation of hPDLSCs, supporting its potential application in periodontal tissues and alveolar bone regeneration.