Cuprorivaite/hardystonite/alginate composite hydrogel with thermionic effect for the treatment of peri-implant lesion.

Peri-implant lesion is a grave condition afflicting numerous indi-viduals with dental implants. It results from persistent periodontal bacteria accumulation causing inflammation around the implant site, which can primarily lead to implant loosening and ultimately the implant loss. Early-stage peri-implant lesions exhibit symptoms akin to gum disease, including swelling, redness and bleeding of the gums surrounding the implant. These signs indicate infection and inflammation of the peri-implant tissues, which may result in bone loss and implant failure. To address this problem, a thermionic strategy was applied by designing a cuprorivaite-hardystonite bioceramic/alginate composite hydrogel with photothermal and Cu/Zn/Si multiple ions releasing property. This innovative approach creates a thermionic effect by the release of bioactive ions (Cu2+ and Zn2+ and SiO32-) from the composite hydrogel and the mild heat environment though the photothermal effect of the composite hydrogel induced by near-infrared light irradiation. The most distinctive advantage of this thermionic effect is to substantially eliminate periodontal pathogenic bacteria and inhibit inflammation, while simultaneously enhance peri-implant osseointegration. This unique attribute renders the use of this composite hydrogel highly effective in significantly improving the survival rate of implants after intervention in peri-implant lesions, which is a clinical challenge in periodontics. This study reveals application potential of a new biomaterial-based approach for peri-implant lesion, as it not only eliminates the infection and inflammation, but also enhances the osteointegration of the dental implant, which provides theoretical insights and practical guidance to prevent and manage early-stage peri-implant lesion using bioactive functional materials.

Periodontitis exacerbates pulmonary hypertension by promoting IFNγ+ T cell infiltration in mice.

Uncovering the risk factors of pulmonary hypertension and its mechanisms is crucial for the prevention and treatment of the disease. In the current study, we showed that experimental periodontitis, which was established by ligation of molars followed by orally smearing subgingival plaques from patients with periodontitis, exacerbated hypoxia-induced pulmonary hypertension in mice. Mechanistically, periodontitis dysregulated the pulmonary microbiota by promoting ectopic colonization and enrichment of oral bacteria in the lungs, contributing to pulmonary infiltration of interferon gamma positive (IFNγ+) T cells and aggravating the progression of pulmonary hypertension. In addition, we identified Prevotella zoogleoformans as the critical periodontitis-associated bacterium driving the exacerbation of pulmonary hypertension by periodontitis, and the exacerbation was potently ameliorated by both cervical lymph node excision and IFNγ neutralizing antibodies. Our study suggests a proof of concept that the combined prevention and treatment of periodontitis and pulmonary hypertension are necessary.

LPS stimulates gingival fibroblasts to express PD-L1 via the p38 pathway under periodontal inflammatory conditions.

OBJECTIVE: The overall aim of this research was to investigate the differences in the expression of programmed death ligand 1 (PD-L1) in human gingival fibroblasts (HGFs) between a periodontal healthy group and a periodontal inflammatory group. and explore the possible mechanism involved. METHODS: Differences in PD-L1 mRNA and protein expression in HGFs from a periodontal healthy group and a periodontal inflammatory group were examined by qPCR and western blotting, respectively, and were further tested after lipopolysaccharide (LPS) stimulation in both groups. The effects of a p38 pathway inhibitor on the changes in p38 phosphorylation levels and PD-L1 expression after LPS stimulation were investigated in both groups. RESULTS: PD-L1 mRNA and protein levels in HGFs in the periodontal inflammatory group were significantly higher than those in the periodontal healthy group (p < 0.05). After 10 µg/mL LPS stimulation, PD-L1 mRNA levels in HGFs from both groups increased significantly (p < 0.05), peaking at 4 h, and the peak was significantly higher in the periodontal inflammatory group than in the periodontal healthy group (p < 0.05). However, PD-L1 protein expression was upregulated only in the inflammatory group (p < 0.05). Inhibition of the p38 pathway in HGFs decreased p38 phosphorylation in both groups (p < 0.05) but this treatment reversed the LPS-induced increase in PD-L1 mRNA and protein levels only in the inflammatory group (p < 0.05). CONCLUSION: In the periodontal inflammatory state, the expression of PD-L1 in HGFs is more easily activated, and may be influenced by the p38 pathway.

[Effects of eicosapentaenoic acid on biological activity and inflammatory factor expression of human gingival fibroblasts].

PURPOSE: To explore the effects of eicosapentaenoic acid (EPA) on biological activity and inflammatory factor expression of human gingival fibroblasts (HGFs). METHODS: The effects of EPA on the activity, morphology and cell cycle of HGFs were observed by living and dead cell staining, immunofluorescence staining and flow cytometry, respectively. HGFs were stimulated by lipopolysaccharides (LPS) of Porphyromonas gingivalis (P. gingivalis) or heat inactivated P. gingivalis, after which the effects of EPA on mRNA and protein expression of IL-6, IL-8 and IL-1ß were observed by real-time PCR and ELISA, respectively. The gene and protein expression of heme oxygenase-1(HO-1) was also detected by real-time PCR and Western blotting, respectively. The data were analyzed with SPSS 22.0 software package. RESULTS: 200 µmol/L EPA inhibited cell activity of HGFs; 100 µmol/L EPA did not affect cell activity and morphology of HGFs, and had no significant effect on cell cycle (P>0.05). EPA significantly downregulated gene expression of IL-6 and IL-1ß, and protein expression of IL-6 stimulated by P. gingivalis LPS and heat-killed P.gingivalis(P<0.05), in a dose-dependent manner. EPA increased gene expression of HO-1 in a dose dependent manner(P<0.05), and upregulated HO-1 protein expression. CONCLUSIONS: EPA significantly inhibits the expression of inflammatory factors without affecting the biological activity of HGFs, which may be related to the induction of HO-1, suggesting the potential role of EPA in the prevention and treatment of periodontitis.

The miR-223-3p Regulates Pyroptosis Through NLRP3-Caspase 1-GSDMD Signal Axis in Periodontitis.

Salivary exosomes contain various components and may play important roles in oral diseases. The purpose of this study was to verify the possible function of miR-223-3p from salivary exosomes in periodontitis. We isolated the salivary exosomes and found that the miR-223-3p content of salivary exosomes from periodontitis was less than the healthy control. Furthermore, we performed dual-luciferase reporter assay and real-time PCR to verify that (NOD)-like receptor (NLR) pyrin domain-containing 3 (NLRP3) was the target of miR-223-3p. When we knocked down the miR-223-3p expression in THP-1-derived macrophages, the expression of NLRP3 and the downstream inflammatory mediators interleukin-1ß (IL-1ß) and IL-6 were upregulated. By using integrated bioinformatics analysis, we found that pyroptosis and cytokine secretion participated in inflammatory gingival tissues. In addition, NLRP3, and the pyroptosis executioner, gasdermin D (GSDMD) was highly active in inflammatory gingival tissues compared with healthy controls by western blotting and immunohistochemistry. In summary, we speculated that miR-223-3p in salivary exosomes might regulate GSDMD-mediated pyroptosis by targeting NLRP3 in periodontitis. Detection of miR-223-3p expression in salivary exosomes could be used as an important non-invasive method to diagnose and evaluate the severity of periodontitis.