Exosomes derived from lipopolysaccharide-preconditioned dental folic cells regulate osteogenic differentiation of periodontal ligament cell in periodontitis

The purpose of this study was to investigate the effect of different concentrations of exosomes (Exos) secreted from dental folic cells (DFCs) preconditioned with lipopolysaccharide (LPS) on the osteogenic differentiation ability of periodontal cells in periodontitis (p-PDLCs) in patients to provide a basis for the prevention and treatment of periodontal disease.

Tissue block and enzyme digestion methods were used to culture DFCs and p-PDLCs. Exosomes were isolated from 250 ng/mL LPS-preconditioned DFCs 24 h later. The characteristics of exosomes were detected by transmission electron microscopy, particle size analysis and Western blotting. The effects of 10 μg/mL and 100 μg/mL exosomes on the osteogenic differentiation of p-PDLCs were detected by RT-PCR and Alizarin red staining.

LPS-pretreated DFC-derived exosomes (L-Exos) are vesicle-like structures with a size between 30-100 nm that positively express CD63 and Alix. Compared with the control group, exosomes significantly upregulated Periostin, Col Ⅰ, and Col Ⅲ expression at 100 μg/mL (P < 0.05), while TGF- β1 was significantly upregulated at 10 μg/mL (P < 0.01). At 7 days after osteogenic induction, mineralized nodules were significantly more abundant in the exosome group than in the control group (P < 0.01), and the results were better at a concentration of 100 μg/mL (P < 0.01).

100 μg/mL L-Exos are better than 10 μg/mL L-Exos in enhancing the osteogenic differentiation ability of p-PDLCs.