Magnesium-enhanced porcine particles using hydrothermal technique improve the osteogenic differentiation of cells

Background: Guided bone regeneration (GBR) uses bone grafts and barrier membranes to block soft tissue invasion and eventually create a new bone. Some studies indicate that a porcine bone graft demonstrates excellent biocompatibility and holds promise as a xenograft for GBR. However, only a few studies have investigated the effectiveness of this biomaterial after magnesium coating in improving osteoblast performance. Aim: This study aimed to prove that the hydrothermal method can be used to coat magnesium oxide (MgO) on the surface of a porcine graft and enhance the biomaterial's property for better osteogenic differentiation of osteoblasts in vitro. Materials and Method: A porcine bone graft was produced, and the hydrothermal method was used to coat 2 mM and 5 mM of MgO on the graft. Material physiochemistry and biocompatibility analyses were performed at days 1, 3, and 5. Results: pH value assay results suggested that MgO slightly increased the alkalinity of the graft. SEM images showed that MgO with some surface roughness was coated on the porcine bone surface, and EDX indicated that the Mg and O element percentages increased by about 5% and 9%, respectively. The porcine graft coated with MgO was rougher than an uncoated porcine graft. FTIR analysis of the porcine graft implied that its chemical structure did not change due to MgO hydrothermal processing. Cell viability assay illustrated the highest cell proliferation with the porcine graft with 5 mM MgO (P < 0.001), and good cell attachment was observed on the graft with immunofluorescence using confocal laser scanning microscopy. Cell differentiation assay results revealed that the porcine graft with 5 mM MgO had the highest alkaline phosphate activity (P < 0.0001) among the uncoated porcine graft and the porcine graft with 2 mM MgO. Relative quantitative polymerase chain reaction (qPCR) at days 1 and 5 revealed upregulated osteoblast gene expression with a statistically significant difference. Conclusion: The porcine graft hydrothermally coated with 5 mM MgO was more biocompatible and enhanced osteoblast differentiation. Thus, the findings of this study indicate that a porcine graft with 5 mM MgO has great potential as a bio-bone graft for guided bone regeneration.