Alveolar Bone Repair Research Articles

Biocompatible chitin-based Janus hydrogel membranes for periodontal repair

Periodontal defects caused by severe periodontitis are a widespread issue globally. Guided tissue regeneration (GTR) using barrier membranes for alveolar bone repair is a common clinical treatment. However, most commercially available collagen barrier membranes are expensive and lack the antibacterial properties essential for effective bone regeneration. Herein, we report a natural polysaccharide chitin hydrogel barrier membrane with a Janus structure (ChT-PDA-p-HAP), featuring high antibacterial and protein-repelling activity on the outer side and good osteogenesis ability on the inner side. This multifunctional membrane is fabricated though a three-step process: (i) dissolution and regeneration of chitin, (ii) co-deposition with polydopamine (PDA) and poly(sulfobetaine methacrylate) (pSBMA), and (iii) coating with gelatin-hydroxyapatite (gelatin-HAP). In vitro cell experiments demonstrated the membrane's high biocompatibility and significant osteogenic activity. In vivo implantation in rats with periodontal defects revealed that the cemento-enamel junction index of the ChT-PDA-p-HAP membrane (1.165 mm) was superior to that of the commercial Bio-Gide® membrane (1.350 mm). This work presents a method for fabricating a chitin-based Janus barrier membrane, potentially expanding the use of chitin in tissue engineering. Statement of significanceThis study introduces a Janus hydrogel membrane based on chitin, tailored for guided tissue regeneration in periodontal defects. By combining antibacterial properties and osteogenic capabilities in a single membrane, the ChT-PDA-p-HAP membrane represents a significant advancement over traditional collagen barriers. Its outer surface, enhanced by Cu2+ and PDA-pSBMA coatings, resists bacterial colonization and protein adhesion effectively, while the inner side, coated with gelatin-HAP, promotes robust bone formation. In vitro experiments demonstrate high biocompatibility and substantial osteogenic differentiation, while in vivo testing in rat models confirms good therapeutic efficacy compared to commercial membranes. This multifunctional approach not only utilizes chitin's abundant natural resource but also integrates simple coating techniques to enhance therapeutic outcomes in periodontal tissue engineering, offering promising avenues for broader biomedical applications.

Microsphere-Composite Hydrogel for Recruiting Stem Cells and Promoting Osteogenic Differentiation.

By recruiting stem cells into scaffolds and differentiating them into osteoblasts, stem cells can be mobilized to directly repair bone defects, which avoids a series of disadvantages of exogenous stem cell implantation. In this study, a microsphere-composite hydrogel for the recruitment and osteogenic differentiation of stem cells was constructed. Methacrylic anhydride modified gelatin (GelMA) and heparin (HepMA), as well as nanohydroxyapatite (nHAP), were used to prepare microspheres followed by adsorbing platelet-derived growth factor BB (PDGF-BB) whose loading efficiency was 53.7 ± 2.2%. Then the microspheres were compounded to the GelMA hydrogel encapsulated with simvastatin (SIM) to obtain microsphere-composite hydrogel GHnH-P@GS. GHnH-P@GS hydrogel could slowly release SIM and PDGF-BB, and the extents of release within 7 days were 44.1 ± 2.0% and 32.8 ± 1.1%. The synergistic effect of small molecule drugs and growth factors not only induced the recruitment of rabbit bone marrow-derived mesenchymal stem cells, but also promoted the osteogenic differentiation of stem cells, which was confirmed by experiments of cell migration, alkaline phosphatase, and alizarin red staining. Collectively, the microsphere-composite hydrogel GHnH-P@GS has a certain reference significance for the design of scaffolds for alveolar bone repair and regeneration.

Role of the Immune System and Stem Cells in Dental Conservation

Background: Dental conservation aims to maintain teeth's appearance and functionality through various procedures. Recent advancements in stem cell research and immune system roles in tooth tissue regeneration highlight their crucial roles in oral health. The immune system is essential for healing after dental treatments and helps maintain oral health. A robust immune response can expedite the healing of damaged oral tissues and prevent further infections, enhancing the outcomes of dental conservation therapies. Purpose: This literature review examines immune system modulation and stem cell therapy in dental conservation, highlighting their potential benefits and challenges in tissue regeneration and treatment outcomes. Methodology: This review analyzes literature on the immune system and stem cell roles in dental tissue regeneration, assessing the effectiveness of immunomodulatory substances and their synergy in healing processes and tissue integration. Result: The review highlights that immunomodulatory substances effectively reduce inflammation and support regeneration, improving dental conservation outcomes. Stem cells, particularly mesenchymal stem cells from dental pulp, show promising results in clinical applications such as pulp regeneration and alveolar bone repair. The combination of immune system modulation and stem cell therapy offers superior outcomes compared to traditional methods, enhancing the quality of tissue regeneration and accelerating healing. However, challenges such as preventing adverse immune responses and ensuring proper integration of transplanted cells with host tissue remain. Ongoing research and technological advancements are expected to enhance dental conservation techniques' effectiveness and efficiency.

Melatonin-coated nanofiber cell sheets promote periodontal regeneration through ROS scavenging and preservation of stemness

Mesenchymal stem cell (MSC)-based cell sheet engineering holds great promise for periodontal tissue engineering and restoring damaged tissues. However, achieving optimal regenerative outcomes remains a challenge. This study introduces a novel approach that integrates melatonin-coated nanofiber fragments (mNFs) into dental follicle stem cell sheets (mNF-CSs) to enhance their regenerative potential. The mNF-CSs were engineered using electrospun poly-L-lactic acid (PLLA) nanofiber sheets fragmented into mNFs and coated with melatonin, a potent antioxidant and osteogenic agent. The mNF-CSs exhibited a homogenous morphology with sustained melatonin release over 21 days, providing a prolonged antioxidative effect critical for tissue regeneration. In vitro experiments demonstrated that mNF-CSs significantly reduced intracellular reactive oxygen species (ROS) levels and upregulated antioxidative proteins such as SOD1 and SOD2, resulting in improved cell viability, maintenance of stemness, and enhanced osteogenic differentiation potential of dental follicle stem cells (DFCs). In vivo studies using both a nude mouse and a rat periodontal defect model demonstrated that mNF-CSs promoted alveolar bone repair and periodontal tissue regeneration, with enhanced retention of MSCs at the defect site and increased expression of periodontal tissue-related markers. Transcriptome analysis revealed the upregulation of genes associated with biomineralization, odontogenesis, and autophagy pathways in mNF-CSs, suggesting their ability to modulate crucial cellular processes for tissue regeneration. Overall, mNF-CSs offer a promising strategy for enhancing periodontal tissue engineering applications, providing a platform for improving bone grafts and regenerative medicine strategies in the context of periodontal diseases.

Electrospun polycaprolactone-chitosan nanofibers on a zinc mesh as biodegradable guided bone-regeneration membranes with enhanced mechanical, antibacterial, and osteogenic properties for alveolar bone-repair applications

Guided bone-regeneration membrane (GBRM) is commonly used in bone-repair surgery because it blocks fibroblast proliferation and provides spatial support in bone-defect spaces. However, the need for removal surgery and the lack of antibacterial properties of conventional GBRM limit its therapeutic applicability for alveolar bone defects. Here we developed a GBRM for alveolar bone-repair and -regeneration applications through double-sided electrospinning of polycaprolactone and chitosan layers on a Zn mesh surface (denoted DSZM). The DSZM showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times higher than that of commercial Bio-Gide membrane. The DSZM exhibited a corrosion rate of ∼17 µm/y and a Zn ion concentration of ∼0.23 µg/ml after 1 month of immersion in Hanks’ solution. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model. Overall, the DSZM fits the requirements for alveolar bone-repair and -regeneration applications as a biodegradable GBRM material due to its spatial support, suitable degradability, cytocompatibility, and antibacterial and osteogenic capabilities. Statement of significanceThis work reports the mechanical properties, antibacterial ability and osteogenic properties of electrospun PCL-CS nanofiber on Zn mesh as biodegradable guided bone-regeneration membrane for alveolar bone-repair applications. Our findings demonstrate that the DSZM prepared by double-sided electrospinning of PCL-CS layers on Zn mesh showed a UTS of ∼25.6 MPa, elongation of ∼16.1%, strength-elongation product of ∼0.413 GPa%, and ultrahigh spatial maintenance ability, and the UTS was over 6 times greater than that of commercial Bio-Gide® membrane. The DSZM showed direct and indirect cytocompatibility with exceptional osteogenic differentiation and calcium deposition toward MC3T3-E1 cells. Further, the DSZM showed strongly sustained antibacterial activity against S. aureus and osteogenesis in a rat critical-sized maxillary defect model.

A five-in-one novel MOF-modified injectable hydrogel with thermo-sensitive and adhesive properties for promoting alveolar bone repair in periodontitis: Antibacterial, hemostasis, immune reprogramming, pro-osteo-/angiogenesis and recruitment

Periodontitis is a chronic inflammatory disease caused by plaque that destroys the alveolar bone tissues, resulting in tooth loss. Poor eradication of pathogenic microorganisms, persistent malignant inflammation and impaired osteo-/angiogenesis are currently the primary challenges to control disease progression and rebuild damaged alveolar bone. However, existing treatments for periodontitis fail to comprehensively address these issues. Herein, an injectable composite hydrogel (SFD/CS/ZIF-8@QCT) encapsulating quercetin-modified zeolitic imidazolate framework-8 (ZIF-8@QCT) is developed. This hydrogel possesses thermo-sensitive and adhesive properties, which can provide excellent flowability and post-injection stability, resist oral fluid washout as well as achieve effective tissue adhesion. Inspirationally, it is observed that SFD/CS/ZIF-8@QCT exhibits a rapid localized hemostatic effect following implantation, and then by virtue of the sustained release of zinc ions and quercetin exerts excellent collective functions including antibacterial, immunomodulation, pro-osteo-/angiogenesis and pro-recruitment, ultimately facilitating excellent alveolar bone regeneration. Notably, our study also demonstrates that the inhibition of osteo-/angiogenesis of PDLSCs under the periodontitis is due to the strong inhibition of energy metabolism as well as the powerful activation of oxidative stress and autophagy, whereas the synergistic effects of quercetin and zinc ions released by SFD/CS/ZIF-8@QCT are effective in reversing these biological processes. Overall, our study presents innovative insights into the advancement of biomaterials to regenerate alveolar bone in periodontitis.

The Effects of Presurgical Orthodontic Treatment on the Outcome of Secondary Bone Graft for Individuals With Cleft Lip and Palate

Background/Objective: Alveolar bone graft (ABG) or repair has become a routine part of treatment protocols for individuals with cleft lip and/or palate. However, the necessity and potential benefits of presurgical orthodontic treatment in influencing the outcomes of secondary alveolar bone grafting remain inconclusive. This systematic review aimed to assess the impact of presurgical orthodontics on preparing patients for secondary alveolar bone grafts. Study Design: The authors systematically searched for relevant articles in PubMed, Web of Science, and Embase databases spanning the period from January 1, 2000, to December 31, 2023, using keywords related to alveolar bone grafting and orthodontic treatment for patients with cleft lip and/or palate. The review encompassed various study designs, including prospective and retrospective studies, observational studies, cross-sectional studies, randomized and nonrandomized clinical trials, cohort studies, and case-control studies. The review adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and the risk of bias was evaluated in studies selected for full-text review. Results: The search strategy identified 809 publications. After initial screening and application of exclusion criteria, 11 studies were included for final review. Three were prospective studies, 8 were retrospective studies, and 3 were cross-sectional cohort studies. On the basis of ROBINS-I and RoB 2 risk assessment, 9 studies were found to be of moderate risk of bias, one study was categorized as of high risk of bias, and 1 study was categorized as low risk of bias. Conclusions: Drawing from the latest and most reliable studies, 7 out of 11 included studies provided compelling evidence that presurgical orthodontics preceding alveolar bone grafting (ABG) leads to significantly improved outcomes compared with cases without presurgical orthodontic intervention. Notably, individuals with specific conditions, such as severely collapsed upper arch and mispositioned upper incisors, appear to derive the greatest benefits from presurgical orthodontic treatment. However, a call for additional studies characterized by high methodological quality and with longer follow-up periods is emphasized to enhance the safety considerations for both practitioners and patients concerning the utilization of presurgical orthodontics in the treatment of individuals with cleft lip and palate.

Dynamic hydrogel–metal–organic framework system promotes bone regeneration in periodontitis through controlled drug delivery

Periodontitis is a prevalent chronic inflammatory disease, which leads to gradual degradation of alveolar bone. The challenges persist in achieving effective alveolar bone repair due to the unique bacterial microenvironment’s impact on immune responses. This study explores a novel approach utilizing Metal–Organic Frameworks (MOFs) (comprising magnesium and gallic acid) for promoting bone regeneration in periodontitis, which focuses on the physiological roles of magnesium ions in bone repair and gallic acid's antioxidant and immunomodulatory properties. However, the dynamic oral environment and irregular periodontal pockets pose challenges for sustained drug delivery. A smart responsive hydrogel system, integrating Carboxymethyl Chitosan (CMCS), Dextran (DEX) and 4-formylphenylboronic acid (4-FPBA) was designed to address this problem. The injectable self-healing hydrogel forms a dual-crosslinked network, incorporating the MOF and rendering its on-demand release sensitive to reactive oxygen species (ROS) levels and pH levels of periodontitis. We seek to analyze the hydrogel’s synergistic effects with MOFs in antibacterial functions, immunomodulation and promotion of bone regeneration in periodontitis. In vivo and in vitro experiment validated the system's efficacy in inhibiting inflammation-related genes and proteins expression to foster periodontal bone regeneration. This dynamic hydrogel system with MOFs, shows promise as a potential therapeutic avenue for addressing the challenges in bone regeneration in periodontitis.Graphical

Polarized M2 macrophages induced by glycosylated nano-hydroxyapatites activate bone regeneration in periodontitis therapy.

To investigate the association between periodontal macrophage polarization states and the alveolar bone levels, and to assess whether glycosylated nano-hydroxyapatites (GHANPs) could improve bone regeneration in periodontitis by inducing macrophage M2 polarization. The change of macrophage polarization state in inflammatory periodontal tissues (with bone loss) was examined using clinical gingival samples. The relationship between macrophage phenotype and bone level in periodontal bone loss and repair was evaluated using a mouse periodontitis model. The effect of GHANPs on macrophage polarization was assessed by the in vitro model of lipopolysaccharide (LPS)-stimulated inflammation. The polarization-related markers were detected by immunofluorescence staining, real-time polymerase chain reaction and enzyme-linked immunosorbent assay analysis. The therapeutic effect of GHANPs on alveolar bone loss was explored in experimental periodontitis by histological staining and micro-CT analysis. A lower macrophage M2/M1 ratio was observed in periodontitis-affected human gingival tissues. The results of animal experiments demonstrated a positive correlation between a lower Arg-1/iNOS ratio and accelerated alveolar bone loss; also, the proportion of Arg-1-positive macrophages increased during bone repair and regeneration. The administration of GHANPs partially restored M2 macrophage polarization after LPS stimulation. GHANPs increased alveolar bone repair and regeneration in experimental periodontitis induced by ligation, potentially related to their macrophage M2 transition regulation. The findings of this study indicate that the induction of macrophage M2 polarization can be considered a viable approach for enhancing inflammatory bone repair. Additionally, GHANPs show potential in the clinical treatment of periodontitis.

Transplanted MSCs promote alveolar bone repair via hypoxia-induced extracellular vesicle secretion.

Mesenchymal stem cell (MSC) therapy is a potential strategy for promoting alveolar bone regeneration. This study evaluated the effects and mechanisms of transplanted MSCs on alveolar bone repair. Mouse alveolar bone defect model was treated using mouse bone marrow mesenchymal stem cell (BMSC) transplantation. The bone repair was evaluated by micro-CT and Masson staining. The conditioned medium of hypoxia-treated BMSCs was co-cultured with normal BMSCs invitro to detect the regulatory effect of transplanted MSCs on the chemotactic and migratory functions of host cells. The mechanisms were investigated using Becn siRNA transfection and western blotting. BMSC transplantation promoted bone defect regeneration. The hypoxic microenvironment induces BMSCs to release multiple extracellular vesicle (EV)-mediated regulatory proteins that promote the migration of host stem cells. Protein array analysis, western blotting, GFP-LC3 detection, and Becn siRNA transfection confirmed that autophagy activation in BMSCs plays a key role during this process. The local hypoxic microenvironment induces transplanted MSCs to secrete a large number of EV-mediated regulatory proteins, thereby upregulating the migration function of the host stem cells and promoting alveolar bone defect regeneration. This process depends on the autophagy-related mechanism of the transplanted MSCs.

A novel approach in biomedical engineering: The use of polyvinyl alcohol hydrogel encapsulating human umbilical cord mesenchymal stem cell-derived exosomes for enhanced osteogenic differentiation and angiogenesis in bone regeneration

Developing effective methods for alveolar bone defect regeneration is a significant challenge in orthopedics. Exosomes from human umbilical cord mesenchymal stem cells (HUMSC-Exos) have shown potential in bone repair but face limitations due to undefined application methods and mechanisms. To address this, HUMSC-Exos were encapsulated in polyvinyl alcohol (PVA) hydrogel (Exo@PVA) to create a novel material for alveolar bone repair. This combination enhanced the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) more effectively than Exos alone. Additionally, Exo@PVA significantly improved alveolar bone regeneration and defect repair in rats. The microRNA-21-5p (miR-21-5p) in Exo@PVA, identified through the GEO database and analyzed via in silico methods, played a crucial role. miR-21-5p promoted BMSC osteogenic differentiation by inhibiting WWP1-mediated KLF5 ubiquitination and enhanced HUVEC angiogenesis by targeting ATP2B4. These findings underscore the potential of an Exo-based approach with PVA hydrogel scaffolds for bone defect repair, operating through the miR-21-5p/WWP1/ATP2B4 signaling axis.

Quercetin through miR-147–5p/Clip3 axis reducing Th17 cell differentiation to alleviate periodontitis

BackgroundQuercetin (QU) plays an important role in treating periodontitis; however, the mechanism through which microRNAs regulate Th17 cell differentiation has not been determined. MethodsQU was administered intragastrically to periodontitis rats once a day for one month. The morphology of alveolar bone was observed by micro-CT, gingival tissue structure was observed by HE staining, IL-6, TNF-α, IL-17A, RORγt, FOXP3 and IL-10 were detected by immunohistochemical staining, and Th17 and Treg cells in the peripheral blood were detected by flow cytometry. CD4+T cells were induced to differentiate into Th17 cells in vitro. Cell viability was determined by CCK8, and IL-17A and RORγt were detected by qPCR. Th17 cells were detected by flow cytometry, microRNA sequencing and bioinformatics analysis were used to screen key microRNAs, the phenotypic changes of Th17 cells were observed after overexpressed microRNAs via mimics. TargetScan database, in situ hybridization, and dual-luciferase reporter experiment were used to predict and prove target genes of microRNAs. The phenotype of Th17 cells was observed after overexpression of microRNA and target gene. ResultsCompared with periodontitis group, the distance from cementoenamel junction(CEJ) to alveolar bone(AB) was decreased, the structure of gingival papilla was improved, IL-6, TNF-α, IL-17, and RORγt were downregulated, FOXP3 and IL-10 were upregulated, the proportion of Th17 decreased and Treg increased in peripheral blood after QU treatment. Compared with Th17 cell group, mRNA levels of IL-17A and RORγt were decreased, and proportion of Th17 cells was significantly lower in the coculture group. MiR-147–5p was low in control group, upregulated in Th17 cell group, and downregulated after QU intervention, it's eight bases were inversely related to 3′UTR of Clip3, miR-147–5p with Clip3 were co-located in cells of periodontal tissue. Compared with those in Th17-mimicsNC + QU cells, the mRNA levels of RORγt and IL-17A upregulated, and proportion of Th17 cells increased in Th17-miR-147–5p + QU cells. The miR-147–5p mimics inhibited the luciferase activity of the WT Clip3 3′UTR but had no effect on the Mut Clip3 3′UTR. Clip3 was significantly downregulated after the overexpression of miR-147–5p. Mimics transfected with miR-147–5p reversed the decrease in the proportion of Th17 cells induced by QU, while the overexpression of Clip3 antagonized the effect of miR-147–5p and further reduced the proportion of Th17 cells. Moreover, the overexpression of miR-147–5p reversed the decreases in the mRNA levels of IL-17 and RORγt induced by QU treatment, while pcDNA3.1 Clip3 treatment further decreased the mRNA levels of IL-17 and RORγt. ConclusionQU reducing inflammatory response and promoting alveolar bone injury and repair, which closely relative to inhibit the differentiation of CD4+T cells into Th17 cells by downregulating miR-147–5p to promote the activation of Clip3.

Cubic liquid crystals containing propolis flavonoids as in situ thermo-sensitive hydrogel depots for periodontitis treatment: Preparation, pharmacodynamics and therapeutic mechanisms

Propolis has a long ethnopharmacological history for oral periodontal diseases treatment. Propolis flavonoids are main active components for anti-inflammation and tissue protection. However, the intractable dissolution properties of propolis flavonoids and complex oral environment pose great challenges for periodontal delivery. In addition, the therapeutic mechanism as well as the therapeutic correlation of inflammation resolution and tissue regeneration remain unclear for propolis flavonoids. In this study, we constructed an in situ thermosensitive depot systems using total flavonoids from propolis-loaded cubic liquid crystals (TFP-CLC) hydrogel for periodontal delivery. TFP-CLC inhibited inflammatory cell infiltration, reactive oxygen species and the expression of inflammatory cytokines of NF-κB and IL-1β. In addition, alveolar bone and collagen were significantly regenerated after TFP-CLC administration according to micro-CT and immunohistochemistry. Mechanism studies suggested that TFP-CLC alleviated inflammation and promoted alveolar bone repair via regulating TLR4/MyD88/NF-κB p65 and RANK/NF-κB signaling pathways, respectively. Correlation analysis further confirmed that the inflammatory resolution produced by TFP-CLC could accelerate periodontal tissue regeneration. In summary, TFP-CLC is a promising multifunctional in situ thermo-sensitive hydrogel depots for periodontitis treatment.

Green tea and hyaluronic acid gel enhance fibroblast activation and improves the gingival healing post-third molar extraction

This study evaluates the effects of a green tea (Camellia sinensis) and hyaluronic acid gel on fibroblast activity and alveolar bone repair following third molar extractions. By examining the gene expression related to cell survival, proliferation, and angiogenesis, the study bridges in vitro findings with clinical outcomes in a split-mouth randomized trial. Human fibroblasts were exposed to the treatment gel, analysing gene expression through RT-qPCR. Twenty participants undergoing bilateral third molar extractions received the test gel on one side and a placebo on the other. Assessments included patient-reported outcomes, professional evaluations, and radiographic analyses at multiple postoperative intervals. The test gel significantly enhanced AKT, CDKs, and VEGF gene expressions, indicating a positive effect on angiogenesis and cell proliferation. Clinically, it resulted in reduced exudate, swelling, and secondary interventions, with radiographs showing improved alveolar bone density after 90 days. The green tea and hyaluronic acid gel significantly improves soft tissue and bone healing post-extraction, offering a promising adjunctive therapy for enhancing postoperative recovery. This gel represents a novel adjuvant treatment option for facilitating improved healing outcomes after third molar extractions, highlighting its potential utility in clinical dental practice.

Inhibition of ZDHHC16 promoted osteogenic differentiation and reduced ferroptosis of dental pulp stem cells by CREB

BackgroundThe repair of bone defects caused by periodontal diseases is a difficult challenge in clinical treatment. Dental pulp stem cells (DPSCs) are widely studied for alveolar bone repair. The current investigation aimed to examine the specific mechanisms underlying the role of Zinc finger DHHC-type palmitoyl transferases 16 (ZDHHC16) in the process of osteogenic differentiation (OD) of DPSCs.MethodsThe lentiviral vectors ZDHHC16 or si-ZDHHC16 were introduced in the DPSCs and then the cells were induced by an odontogenic medium for 21 days. Subsequently, Quantitate Polymerase Chain Reaction (PCR), immunofluorescent staining, proliferation assay, ethynyl deoxyuridine (EdU) staining, and western blot analysis were used to investigate the specific details of ZDHHC16 contribution in OD of DPSCs.ResultsOur findings indicate that ZDHHC16 exhibited a suppressive effect on cellular proliferation and oxidative phosphorylation, while concurrently inducing ferroptosis in DPSCs. Moreover, the inhibition of ZDHHC16 promoted cell development and OD and reduced ferroptosis of DPSCs. The expression of p-CREB was suppressed by ZDHHC16, and immunoprecipitation (IP) analysis revealed that ZDHHC16 protein exhibited interconnection with cAMP-response element binding protein (CREB) of DPSCs. The CREB suppression reduced the impacts of ZDHHC16 on OD and ferroptosis of DPSCs. The activation of CREB also reduced the influences of si-ZDHHC16 on OD and ferroptosis of DPSCs.ConclusionsThese findings provide evidences to support a negative association between ZDHHC16 and OD of DPSCs, which might be mediated by ferroptosis of DPSCs via CREB.

Leptin receptor (+) stromal cells respond to periodontitis and attenuate alveolar bone repair via CCRL2-mediated Wnt inhibition.

The impaired bone healing in tooth extraction sockets due to periodontitis presents a major obstacle to restoring oral health. The mechanisms regulating the osteogenic capacity of jawbone-derived stromal cells in the periodontitis microenvironment remain elusive. Leptin receptor (LepR) expressing stromal cells, which largely overlap with Cxcl12-abundant reticular (CAR) cells in bone tissue, rapidly proliferate and differentiate into bone-forming cells during extraction socket healing to support alveolar bone repair. In this study, we identify that CCRL2 is significantly expressed and inhibits osteogenesis in LepR+/CAR cells of alveolar bones with periodontitis. The Ccrl2-KO mice exhibit significant improvements in bone healing in extraction sockets with periodontitis. Specifically, the binding of CCRL2 to SFRP1 on the surface of LepR+/CAR cells can amplify the suppressive effect of SFRP1 on Wnt signaling under inflammation, thus hindering the osteogenic differentiation of LepR+/CAR cells and resulting in poor bone healing in extraction sockets with periodontitis. Together, we clarify that the CCRL2 receptor of LepR+/CAR cells can respond to periodontitis and crosstalk with Wnt signaling to deteriorate extraction socket healing.

Electrospun L-Lysine/Amorphous Calcium Phosphate Loaded Core-Sheath Nanofibers for Managing Oral Biofilm Infections and Promoting Periodontal Tissue Repairment.

Periodontitis, a chronic inflammatory disease prevalent worldwide, is primarily treated through GTR for tissue regeneration. The efficacy of GTR, however, remains uncertain due to potential infections and the intricate microenvironment of periodontal tissue. Herein, We developed a novel core-shell structure multifunctional membrane using a dual-drug-loaded coaxial electrospinning technique (Lys/ACP-CNF), contains L-lysine in the outer layer to aid in controlling biofilms after GTR regenerative surgery, and ACP in the inner layer to enhance osteogenic performance for accelerating alveolar bone repair. The biocompatibility and cell adhesion were evaluated through CCK-8 and fluorescence imaging, respectively. The antibacterial activity was assessed using a plate counting assay. ALP, ARS, and RT-qPCR were used to examine osteogenic differentiation. Additionally, an in vivo experiment was conducted on a rat model with acute periodontal defect and infection. Micro-CT and histological analysis were utilized to analyze the in vivo alveolar bone regeneration. Structural and physicochemical characterization confirmed the successful construction of the core-shell fibrous structure. Additionally, the Lys/ACP-CNF showed strong antibacterial coaggregation effects and induced osteogenic differentiation of PDLSCs in vitro. The in vivo experiment confirmed that Lys/ACP-CNF promotes new bone formation. Lys/ACP-CNF rapidly exhibited excellent antibacterial activity, protected PDLSCs from infection, and was conducive to osteogenesis, demonstrating its potential application for clinical periodontal GTR surgery.

Ozone therapy effect in medication-related osteonecrosis of the jaw as prevention or treatment: microtomographic, confocal laser microscopy and histomorphometric analysis.

This study aimed to evaluate the efficacy of ozone therapy in the preoperative (prevention) and/or postoperative (treatment) of MRONJ. Forty male Wistar rats were caudally treated with zoledronic acid (ZOL) and to ozone therapy before extraction (prevention, POG), after extraction (treatment, TOG), or both (prevention and treatment, TPOG), and treated with saline (SAL). The animals received intramuscular fluorochrome (calcein and alizarin), and 28 days postoperatively, they were euthanized, and the tissues were subjected to microtomographic computed tomography (microCT), LASER confocal, and histomorphometric analyses. Micro-CT showed a higher bone volume fraction average in all groups than that in the ZOL group (P < 0.001), the ZOL group showed high porosity (P = 0.03), and trabecular separation was greater in the TOG group than in the POG group (P < 0.05). The mineral apposition rate of the POG group was high (20.46 ± 6.31) (P < 0.001), followed by the TOG group (20.32 ± 7.4). The TOG group presented the highest mean newly formed bone area (68.322 ± 25.296) compared with the ZOL group (P < 0.05), followed by the SAL group (66.039 ± 28.379) and ZOL groups (60.856 ± 28.425). Ozone therapy modulated alveolar bone repair in animals treated with ZOL, mainly after surgery trauma, leading to bone formation as healing tissue. Osteonecrosis has been a challenge in dentistry, and owing to the lack of a consensus regarding therapy, studies presenting new therapies are important, and ozone has been one of the therapies explored empirically.

Interleukin-17 alleviates erastin-induced alveolar bone loss by suppressing ferroptosis via interaction between NRF2 and p-STAT3.

To investigate the relationship between interleukin-17 (IL-17), ferroptosis and osteogenic differentiation. We first analysed the changes in ferroptosis-related molecules in experimental periodontitis models. The effects of erastin, a small-molecule ferroptosis inducer, and IL-17 on alveolar bone loss and repair in animal models were then investigated. Primary mouse mandibular osteoblasts were exposed to erastin and IL-17 in vitro. Ferroptosis- and osteogenesis-related genes and proteins were detected. Further, siRNA, immunofluorescence co-localization and immunoprecipitation were used to confirm the roles of the nuclear factor erythroid-2-related factor 2 (NRF2) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3), as well as their interaction. The levels of NRF2, glutathione peroxidase 4 and solute carrier family 7 member 11 were lower in the ligated tissues than in normal periodontal tissues. Alveolar bone loss in an in vivo experimental periodontitis model was aggravated by erastin and alleviated by IL-17. In vitro, IL-17 ameliorated erastin-inhibited osteogenic differentiation by reversing ferroptosis. Altered NRF2 expression correlated with changes in ferroptosis-related molecules and osteogenesis. Furthermore, the physical interaction between NRF2 and p-STAT3 was confirmed in the nucleus. In IL-17 + erastin-stimulated osteoblasts, the p-STAT3-NRF2 complex might actively participate in the downstream transcription of ferroptosis- and osteogenesis-related genes. IL-17 administration conferred resistance to erastin-induced osteoblast ferroptosis and osteogenesis. The possible mechanism may involve p-STAT3 directly interacting with NRF2.

Acetylsalicylic Acid Promotes Osteogenic Differentiation of Human Dental Pulp Mesenchymal Stem Cells and Regeneration of Alveolar Bone in Experimental Periodontitis Rats

Background. Periodontitis is characterized by bone resorption and periodontal tissue destruction owing to oral microbiota, mechanical stress, and systemic diseases such as diabetes mellitus. Human dental pulp mesenchymal stem cells (hDPMSCs) were analyzed as potential candidates for periodontal tissue regeneration. Acetylsalicylic acid (ASA), also known as aspirin, has been shown to promote osteogenic differentiation of mesenchymal stem cells. We investigated the effect of ASA pretreatment on periodontitis in order to achieve a more appealing prognosis of bone resorption. Methods. The effect of ASA on cell proliferation was detected by the CCK-8 assay, and alkaline phosphatase (ALP) staining, alizarin red staining (ARS), and western blot were used to investigate the effect of different ASA concentrations on hDPMSCs’ osteogenic differentiation and possible signaling pathways. Periodontitis was induced for 4 weeks. Stem cells pretreated with 50 µg/mL of ASA were transplanted into six-week-old male Sprague-Dawley rats by local and systemic injection once a week for two weeks. Four weeks after cell therapy, the rats were sacrificed for sampling to complete the molecular and morphological experiments. Results. In vitro experiments revealed that 50 µg/mL of ASA had a significant effect on cell osteogenic differentiation. That is, when ASA was administered, the MAPK signaling pathway was activated. Notably, further vivo experiments revealed that ASA-hDPMSCs increased the area of bone regeneration and the OPG/RANKL ratio, suppressed TNF-α and IL-1 expression, and promote alveolar bone repair. Conclusion. Our study extends the findings of previous research, firstly demonstrating that the use of ASA-pretreated hDPMSCs offers a novel therapy for the treatment of periodontitis for future clinical application.