Role of METTL3-mediated m6A modification in osteogenic differentiation of periodontal ligament stem cells extracted from adult periodontal ligaments ex-vivo.

Periodontal ligament stem cells (PDLSCs) are identified as candidate cells for the regeneration of periodontal and alveolar bone tissues. This research was to analyze the effect of methyltransferase-like 3 (METTL3)-mediated m6A modification on the osteogenic differentiation of PDLSCs extracted from adult periodontal ligaments (PDLs) ex-vivo. From June 2022 to October 2022, 27 patients undergoing orthodontic treatment in our hospital were selected as the research population, with 31 teeth extracted in total. PDLSCs were isolated from PDLs by tissue block culture, and the results were analyzed. Then PDLSCs were induced to differentiate into osteoblasts, and changes in METTL3 and m6A levels during differentiation were observed. Additionally, abnormal METTL3 expression vectors were constructed and transfected into PDLSCs to observe the influence of METTL3 on the biological behavior and osteogenic differentiation of PDLSCs. PDLSCs isolated from ex-vivo PDLs were predominantly spindle-shaped, with high CD73, CD90 and CD105 levels and low CD11b, CD34 and CD45 levels, showing the characteristics of stem cells. Spearman correlation coefficients identified a positive connection between Runx2, Sp7, Alp, Bglap, METTL3 and m6A levels and osteogenic differentiation incubation time (P<0.05). As METTL3 expression was increased, the proliferation capacity and osteogenic differentiation ability of PDLSCs were enhanced (P<0.05), and the content of m6A was increased (P<0.05). However, the activity and osteogenic differentiation ability of PDLSCs was decreased after silencing METTL3 (P<0.05). In conclusion, METTL3-mediated m6A modification promoted the osteogenic differentiation of PDLSCs extracted from adult PDLs ex vivo. This study offered a novel understanding of the mechanisms underlying osteogenic differentiation, and implied a possible method for accelerating bone formation.

Single-cell RNA sequencing and traditional RNA sequencing reveals the role of cancer-associated fibroblasts in oral squamous cell carcinoma cohort.

Chronic inflammation of the alveolar bones and connective tissues supporting teeth causes periodontal disease, one of the most prevalent infectious diseases in humans. It was previously reported that oral cancer was the sixth most common cancer in the world, followed by squamous cell carcinoma. Periodontal disease has been linked to an increased risk for oral cancer in some studies, and these studies have found a positive relationship between oral cancer and periodontal disease. In this work, we aimed to explore the potential correlation between oral squamous cell carcinoma (OSCC) and Periodontal disease. The single-cell RNA sequence analysis was applied to explore the genes that were closely associated with cancer-associated fibroblasts (CAFs). the head and neck squamous cell carcinoma. The Single sample Gene Set Enrichment Analysis (ssGSEA) algorithm was applied to explore the scores of CAFs. Subsequently, the differentially expressed analysis was applied to explore the CAFs-related genes that play a key role in the OSCC cohort. The LASSO regression analysis and the COX regression analysis were applied to construct the CAFs-based periodontal disease-related risk model. In addition, the correlation analysis was used to explore the correlation between the risk model and clinical features, immune-related cells, and immune-related genes. By using the single-cell RNA sequence analysis, we successfully obtained the biomarkers for the CAFs. Finally, we successfully obtained a six-CAFs-related genes risk model. The ROC curve and survival analysis revealed that the risk model showed good predictive value in OSCC patients. Our analysis successfully provided a new direction for the treatment and prognosis of OSCC patients.

A bio-inspired versatile free-standing membrane for oral cavity microenvironmental monitoring and remineralization to prevent dental caries.

The fast monitoring of oral bacterial infection, bacterial clearance and repairing of enamel damage caused by dental caries relies on an effective way of monitoring, killing and repairing in situ, but presents a major challenge in oral healthcare. Herein, we developed a bio-inspired versatile free-standing membrane by filling TiO2 nanotube arrays with ß-sheet-rich silk fibroin and cleaving them from Ti foil, as inspired by nacre or enamel-like structures. The robust transparent membrane exhibited good mechanical properties, and could indicate acid-base microenvironment variation and the infection of S. mutans in a 5 min test by loading cyanidin cations in the membrane. Meanwhile, it can be used for photocatalysis and nanoreservoirs ascribed to TiO2 nanotubes, to kill and remove 99% of S. mutans bacteria under interval UV irradiation with low-power density, and load functional peptide to induce the remineralization on the etched-enamel for long-term treatment, tested in vitro and in vivo. The mechanical property of repaired enamel is improved in comparison. This bio-inspired constructed membrane would be applied in the prevention and treatment of oral cavity related diseases, such as enamel demineralization and dental caries, etc.

Application of Porous Polyetheretherketone Scaffold/Vancomycin-Loaded Thermosensitive Hydrogel Composites for Antibacterial Therapy in Bone Repair.

Polyetheretherketone (PEEK) has been widely used in bone repair, but it often fails due to bacterial infection. Herein, a high-strength porous polyetheretherketone scaffold (ps-PK) loaded with antibacterial drug-loaded hydrogel strategy is proposed. The prepared ps-PK possesses high porosity (30.8-64.7%) and the compression modulus is between 0.4 and 0.98 GPa. The interconnected pore-type structure endows it with a drug loading capacity. Poly(D,L -lactic acid-co-glycolic acid)-b-Poly(ethylene glycol)-b-Poly(D,L -lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) thermoresponsive hydrogels loaded with vancomycin are used as the drug sustained-release system. The vancomycin-loaded hydrogels in the solution state at a low temperature are filled into a porous polyetheretherketone scaffold (ps-PK-VGel) and formed a gel state after implantation in vivo. The antibacterial rate of ps-PK-VGel against methicillin-resistant staphylococcus aureus in vitro is 99.7% and histological observation in vivo demonstrates that the ps-PK-VGel shows obvious antibacterial activity. Given its excellent antibacterial ability and mechanical properties, the porous PEEK scaffold composite drug-loaded thermosensitive hydrogel has great potential in bone repair surgery applications.

Implantable zoledronate-PLGA microcapsules ameliorate alveolar bone loss, gingival inflammation and oxidative stress in an experimental periodontitis rat model.

The effect of implantable Zoledronate-PLGA microcapsules (PLGA-ZOL) in periodontitis remains unclear. In this study, we aimed to explore the potential role of PLGA-ZOL in protecting periodontitis and elucidate the underlying mechanism. A rat model of periodontitis was established by ligation the mandibular first molars, then PLGA-ZOL was implanted. The healing volume was scanned by cone-beam computed tomography. Cytokine levels in the gingival tissues were determined by ELISA and RT-PCR. Oxidative stress was indicated by detecting superoxide dismutase concentration and catalase activity. After periodontitis model was successfully established in rats, PLGA-ZOL treatment significantly attenuated alveolar bone loss, as indicated by the increased total healing volume, bone volume/tissue volume and osteoprotegerin level, as well as decreased sRANKL level. PLGA-ZOL treatment also suppressed the inflammatory activities by inhibiting pro-inflammatory cytokine production (TNF-α, IL-1ß) but increasing anti-inflammatory cytokine secretion (IL-10). Furthermore, PLGA-ZOL was found to ameliorate oxidative stress in gingival tissues. In conclusion, PLGA-ZOL microcapsules ameliorate alveolar bone loss, gingival inflammation and oxidative stress in an experimental rat model of periodontitis.

Effective Oxidation-Responsive Polyester Nanocarriers for Anti-Inflammatory Drug Delivery.

BACKGROUND: High levels of oxidants, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), are typical characteristics of an inflammatory microenvironment and are closely associated with a various inflammatory pathologies, eg, cancer, diabetes, atherosclerosis, and neurodegenerative diseases. Therefore, the delivery of anti-inflammatory drugs by oxidation-responsive smart systems would be an efficient anti-inflammatory strategy that benefits from the selective drug release in an inflammatory site, a lower treatment dose, and minimizes side effects. PURPOSE: In this study, we present the feasibility of an oxidation-sensitive PEGylated alternating polyester, methoxyl poly(ethylene glycol)-block-poly(phthalic anhydride-alter-glycidyl propargyl ether) (mPEG-b-P(PA-alt-GPBAe)), as novel nanocarrier for curcumin (CUR), and explore the application in anti-inflammatory therapy. METHODS: The copolymers used were obtained by combining a click reaction and a ring-opening-polymerization method. CUR was loaded by self-assembly. The in vitro drug release, cytotoxicity toward RAW 264.7 cells and cellular uptake were investigated. Furthermore, the anti-inflammatory effects of CUR-loaded polymeric nanoparticles (NPs-CUR) were investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and tested in a murine model of ankle inflammation. RESULTS: Fast drug release from NPs-CUR was observed in trigger of 1 mM H2O2 in PBS. Compared with NPs and free drugs, the significant anti-inflammatory potential of NPs-CUR was proven in activated RAW 264.7 cells by inhibiting the production of TNF-α, IL-1ß, and IL-6 and increasing the level of an anti-inflammatory cytokine IL-10. Finally, a local injection of NPs-CUR at a dose of 0.25 mg/kg suppressed the acute ankle inflammatory response in mice by histological observation and further reduced the expression of pro-inflammatory cytokines in the affected ankle joints compared to that of free CUR. CONCLUSION: Both the significant in vitro and in vivo anti-inflammatory results indicated that our oxidation responsive polymeric nanoparticles are promising drug delivery systems for anti-inflammatory therapy.

[Construction of eukaryotic co-expression vector of Porphyromonas gingivalis outer membrane protein ragB and glucocorticoid-induced tumor necrosis factor receptor ligand (GITRL) and its immunogenic analysis].

AIM: To construct eukaryotic co-expression vector of Porphyromonas gingivalis outer membrane protein ragB and mouse glucocorticoid-induced tumor necrosis factor receptor ligand (mGITRL) and to analyze its immunogenicity in vivo. METHODS: The ragB gene was obtained from pMD18-T-ragB, and then cloned into the eukaryotic expression vector pIRES and pIRES-mGITRL, respectively. The eukaryotic expression vectors: pIRES-ragB and pIRES-ragB-mGITRL were identified by double enzyme digestion and DNA sequencing, then transfected into COS7 cells by Lipofectamine(TM);2000. The expressions of ragB or mGITRL in COS7 cells were detected by Western blotting. The mice were immunized with the recombinant pIRES-ragB-mGITRL plasmid. The serum antibody level was determined by ELISA. RESULTS: pIRES-ragB and pIRES-ragB-mGITRL plasmids were successfully constructed. Western blotting showed that the targeted gene was over-expressed in COS7 cells and skeletal muscle cells, respectively. The high titers of antibodies against RagB were detected in mouse serum. CONCLUSION: The construction of pIRES-ragB-mGITRL co-expression vector provides the experimental basis for Porphyromonas gingivalis vaccine research, prevention and treatment of periodontitis.

[Characterization of polycyclic aromatic hydrocarbons dissolved in nonionic surfactants].

Using three typical nonionic surfactants (Tween80, Tween20 and Triton X-100), the solubilization of four kinds of polycyclic aromatic hydrocarbons (PAHs) e.g. naphthalene, phenanthrene, fluorene and pyrene, were characterized. It was found that not only nonionic surfactants could enhance the solubilization of PAHs greatly in the range of concentration above critical micellar concentration (CMC), but also the solubility had the linear relationship with the concentration of nonionic surfactants. The effect of solubilization enhancement at three surfactants was Triton X-100 > Tween80 > Tween20. In the three nonionic surfactants solution the micelle-aqueous phase partitioning coefficient (K(m)) had very good linear proportional to the octanol-water partitioning coefficient (Kow) for the four tested PAHs.

[The influence on the biodegradation of phenanthrene by nonionic surfactant, Tween20].

The objective of this study was to quantify the bioavailability of phenanthrene solubilized in surfactants by a mixed phenanthrene-degrading culture isolated from the petroleum contaminated soils. An nonionic surfactant, Tween20, was used. The effects of Tween20 on the microbial degradation of phenanthrene were evaluated depending on the rotary flasks experiments. The results showed that the concentrations of Tween20 above the critical micelle concentration (CMC) could increase the solubility of phenanthrene on great extent and were not toxic to the phenanthrene-degrading bacteria, and that the presence of surfactant micelles did not inhibit the biodegradation of phenanthrene. Phenanthrene solubilized in the micelles of Tween20 in liquid media was bioavailable and degradable by the mixed culture of bacteria.