Guided Bone Regeneration (GBR) relies on membrane nails to stabilize barrier membranes and promote osseous healing. However, conventional titanium nails need secondary removal surgeries and may impair osteogenesis. Magnesium (Mg), a biodegradable metal, offers a promising alternative due to its degradability, biocompatibility, and osteoconductive properties. However, Mg-based alloys often exhibit rapid and localized corrosion, which may result in premature failure, thus limiting its clinical applicability. Therefore, in this study, two pure Mg with varying purity—commercially pure Mg (CP-Mg, purity: 99.98 wt.%) and ultrahigh-pure Mg (UHP-Mg, purity: 99.99937 wt.%)—were employed to fabricate the membrane nails to enhance their corrosion performance. The mechanical, degradation, and biological properties of the materials were studied by mechanical tests, in vitro corrosion and cell test, and in vivo implant tests. The results demonstrate that the grain sizes of CP-Mg and UHP-Mg are 38 µm and 27 µm, respectively. Both CP-Mg and UHP-Mg membrane nails are capable of shear forces of approximately 55 N, with no significant difference observed between the two materials, fulfilling the practical requirements for clinical applications in membrane fixation. However, in vitro corrosion test reveals that the degradation rate of UHP-Mg membrane nails is significantly lower than that of CP-Mg membrane nails, with improved degradation uniformity, which may mitigate premature mechanical failure resulting from rapid localized degradation. The cellar test shows that UHP-Mg has superior biological properties. Furthermore, in vivo experiments demonstrated that UHP-Mg membrane nails exhibited a slower and more uniform degradation post-implantation, with no positional migration or detachment observed within 4 weeks, and no significant inflammatory response was induced during the experimental period. Additionally, all bone morphology indices in the degraded area were superior to those in CP-Mg membrane nails, demonstrating enhanced osteogenesis. Therefore, UHP-Mg exhibits high potential for clinical application as a barrier membrane fixation nail material. This study provides a theoretical foundation for the future clinical application of degradable Mg implant devices.

Recent studies have suggested that long-term application of anti-angiogenic drugs may impair oral mucosal wound healing. This study investigated the effect of sunitinib on oral mucosal healing impairment in mice and the therapeutic potential of Bifidobacterium breve (B. breve). A mouse hard palate mucosal defect model was used to investigate the influence of sunitinib and/or zoledronate on wound healing. The volume and density of the bone under the mucosal defect were assessed by micro-computed tomography (micro-CT). Inflammatory factors were detected by protein microarray analysis and enzyme-linked immunosorbent assay (ELISA). The senescence and biological functions were tested in oral mucosal stem cells (OMSCs) treated with sunitinib. Ligated loop experiments were used to investigate the effect of oral B. breve. Neutralizing antibody for interleukin-10 (IL-10) was used to prove the critical role of IL-10 in the pro-healing process derived from B. breve. Results showed that sunitinib caused oral mucosal wound healing impairment in mice. In vitro, sunitinib induced cellular senescence in OMSCs and affected biological functions such as proliferation, migration, and differentiation. Oral administration of B. breve reduced oral mucosal inflammation and promoted wound healing via intestinal dendritic cells (DCs)-derived IL-10. IL-10 reversed cellular senescence caused by sunitinib in OMSCs, and IL-10 neutralizing antibody blocked the ameliorative effect of B. breve on oral mucosal wound healing under sunitinib treatment conditions. In conclusion, sunitinib induces cellular senescence in OMSCs and causes oral mucosal wound healing impairment and oral administration of B. breve could improve wound healing impairment via intestinal DCs-derived IL-10.