Effect of Osteogenic Metabolic Differentiation of Silver Nanoparticles-based Periodontal Ligament Fibroblasts on Orthodontic Tooth Movement

It was to clarify the effects of silver nanoparticles (AgNPs) on biological functions of human periodontal ligament fibroblasts (hPDLFs). Methods: AgNPs were synthesized using a tannic acid reduction method and characterized accordingly. Fifteen Sprague-Dawley rats were randomly assigned to Normal group, Group A (orthodontic tooth movement after alveolar bone defect repair with a blood clot), and Group B (orthodontic tooth movement after alveolar bone defect repair with AgNPs), with five rats in each group. Morphological changes in periodontal tissues were visualized. hPDLFs were treated with 0 μM (Ctrl), 25 μM (L-AgNPs), 50 μM (M-AgNPs), and 100 μM (H-AgNPs) AgNPs to assess cell proliferation via the MTT assay, calcification via alizarin red staining, and osteogenic differentiation and genes/proteins’ expression associated with the I3K/Akt signaling pathway through quantitative polymerase chain reaction and Western blot. Results: AgNP diameter was approximately 20 nm. Relative to the normal group, both Group A and Group B exhibited increased widths of the periodontal ligament (PDL) while displaying a decrease in cell counts within the PDL (P < 0.05). Furthermore, the L-AgNPs, M-AgNPs, and H-AgNPs groups exhibited a notable elevation in the number of calcified nodules in hPDLFs, along with elevated alkaline phosphatase, Runx2, osteocalcin, osterix, type I collagen, phosphorylated phosphoinositide 3-kinase, and phosphorylated protein kinase B versus Ctrl (P < 0.05). Conclusion: AgNPs are beneficial in enhancing the biological functions of the PDL, promoting the repair and regeneration of periodontal tissues, indicating their potential clinical value in orthodontic treatments.