ROS-scavenging biomaterials for periodontitis

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.

Erythrocyte-Like Mesoporous PDA@CeO2 Nanozyme with Dual Drugs for Periodontitis Treatment

Periodontitis is a chronic oral inflammatory disease with the characteristic of excess oxidative stress in the inflammatory site, dramatically decreasing the quality of life. Studies show that nanozymes can be ideal candidates for ROS scavenging in periodontitis. Here, we design a multipath anti-inflammatory mesoporous polydopamine@cerium oxide nanobowl (mPDA@CeO2 NB) with multienzyme mimicking properties, which combines the advantages of both CeO2 NP and mPDA NB for synergistically eliminating reactive oxygen species (ROS), including hydroxyl radical (•OH), hydrogen peroxide (H2O2), and superoxide (O2•-). Besides, the erythrocyte-like structure of mNBs makes them a facility for cell uptake, and the mesopores can load both hydrophobic and hydrophilic drugs for combined anti-inflammatory therapy. In vitro and in vivo experiments prove that the combination of CeO2 and mPDA can synergistically achieve multiple complementary ROS eliminations and suppression of ROS-induced inflammation. Moreover, the ROS regulation plus anti-inflammatory drugs in one mPDA@CeO2 NB prevents the progression of periodontitis in a mouse model. Therefore, the design of mPDA@CeO2 NB with these excellent properties provides a therapeutic strategy for inflammatory diseases.

Injectable Thermosensitive Gel CH-BPNs-NBP for Effective Periodontitis Treatment through ROS-Scavenging and Jaw Vascular Unit Protection

Periodontitis, a prevalent inflammatory condition in the oral cavity, is closely associated with oxidative stress-induced tissue damage mediated by excessive reactive oxygen species (ROS) production. The jaw vascular unit (JVU), encompassing both vascular and lymphatic vessels, plays a crucial role in maintaining tissue fluid homeostasis and contributes to the pathological process in inflammatory diseases of the jaw. This study presents a novel approach for treating periodontitis through the development of an injectable thermosensitive gel (CH-BPNs-NBP). The gel formulation incorporates black phosphorus nanosheets (BPNs), which are notable for their ROS-scavenging properties, and dl-3-n-butylphthalide (NBP), a vasodilator that promotes lymphatic vessel function within the JVU. These results demonstrate that the designed thermosensitive gel serve as a controlled release system, delivering BPNs and NBP to the site of inflammation. CH-BPNs-NBP not only protects macrophages and human lymphatic endothelial cells from ROS attack but also promotes M2 polarization and lymphatic function. In in vivo studies, this work observes a significant reduction in inflammation and tissue damage, accompanied by a notable promotion of alveolar bone regeneration. This research introduces a promising therapeutic strategy for periodontitis, leveraging the unique properties of BPNs and NBP within an injectable thermosensitive gel.

Oxidative Stress and FOXO-1 Relationship in Stage III Periodontitis

OBJECTIVES

8-Hydroxideoxyguanosine (8-OHdG) is a marker of oxidative stress, and Forkhead Box-O1 (FOXO1) is a transcription factor and signaling integrator in cell and tissue homeostasis. This study aims to determine FOXO1 and 8-OHdG levels in serum and saliva samples of periodontitis patients and to evaluate their relationship with clinical periodontal parameters.

MATERIALS AND METHODS

Twenty healthy individuals, twenty generalized Stage III Grade B periodontitis patients, and nineteen generalized Stage III Grade C periodontitis patients were included in the study. Clinical periodontal parameters (plaque index (PI), probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL)) were recorded. Salivary and serum 8-OHdG and FOX-O1 levels were analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Clinical periodontal parameters showed a statistically significant increase in periodontitis groups compared to the control group (p < 0.05). 8-OHdG salivary levels were significantly higher in both periodontitis groups compared to the control group. The salivary FOXO1 levels were significantly lower in both periodontitis groups compared to the control group. Salivary FOXO1 level had a low-grade negative correlation with BOP and salivary 8-OHdG level.

CONCLUSIONS

While reactive oxygen species increase in periodontal inflammation, low expression of FOXO1, an important transcription factor for antioxidant enzymes, supports that this molecule plays a vital role in tissue destruction, and FOXO1 can be seen as a potential immune modulator.

CLINICAL RELEVANCE

The role of FOXO1 in supporting antioxidant defense may suggest that FOXO1 is a candidate target for periodontitis treatment.

Emerging polymeric materials for treatment of oral diseases: design strategy towards a unique oral environment

Oral diseases are prevalent but challenging diseases owing to the highly movable and wet, microbial and inflammatory environment. Polymeric materials are regarded as one of the most promising biomaterials due to their good compatibility, facile preparation, and flexible design to obtain multifunctionality. Therefore, a variety of strategies have been employed to develop materials with improved therapeutic efficacy by overcoming physicobiological barriers in oral diseases. In this review, we summarize the design strategies of polymeric biomaterials for the treatment of oral diseases. First, we present the unique oral environment including highly movable and wet, microbial and inflammatory environment, which hinders the effective treatment of oral diseases. Second, a series of strategies for designing polymeric materials towards such a unique oral environment are highlighted. For example, multifunctional polymeric materials are armed with wet-adhesive, antimicrobial, and anti-inflammatory functions through advanced chemistry and nanotechnology to effectively treat oral diseases. These are achieved by designing wet-adhesive polymers modified with hydroxy, amine, quinone, and aldehyde groups to provide strong wet-adhesion through hydrogen and covalent bonding, and electrostatic and hydrophobic interactions, by developing antimicrobial polymers including cationic polymers, antimicrobial peptides, and antibiotic-conjugated polymers, and by synthesizing anti-inflammatory polymers with phenolic hydroxy and cysteine groups that function as immunomodulators and electron donors to reactive oxygen species to reduce inflammation. Third, various delivery systems with strong wet-adhesion and enhanced mucosa and biofilm penetration capabilities, such as nanoparticles, hydrogels, patches, and microneedles, are constructed for delivery of antibiotics, immunomodulators, and antioxidants to achieve therapeutic efficacy. Finally, we provide insights into challenges and future development of polymeric materials for oral diseases with promise for clinical translation.

Multifunctional Metal-Phenolic Composites Promote Efficient Periodontitis Treatment via Antibacterial and Osteogenic Properties

Periodontitis, a complex inflammatory disease initiated by bacterial infections, presents a significant challenge in public health. The increased levels of reactive oxygen species and the subsequent exaggerated immune response associated with periodontitis often lead to alveolar bone resorption and tooth loss. Herein, we develop multifunctional metal-phenolic composites (i.e., Au@MPN-BMP2) to address the complex nature of periodontitis, where gold nanoparticles (AuNPs) are coated by metal-phenolic networks (MPNs) and bone morphogenetic protein 2 (BMP2). In this design, MPNs exhibit remarkable antibacterial and antioxidant properties, and AuNPs and BMP2 promote osteogenic differentiation of bone marrow mesenchymal stem cells under inflammatory conditions. In a rat model of periodontitis, treatment with Au@MPN-BMP2 leads to notable therapeutic outcomes, including mitigated oxidative stress, reduced progression of inflammation, and the significant prevention of inflammatory bone loss. These results highlight the multifunctionality of Au@MPN-BMP2 nanoparticles as a promising therapeutic approach for periodontitis, addressing both microbial causative factors and an overactivated immune response. We envision that the rational design of metal-phenolic composites will provide versatile nanoplatforms for tissue regeneration and potential clinical applications.

Melatonin-Derived Carbon Dots with Free Radical Scavenging Property for Effective Periodontitis Treatment via the Nrf2/HO-1 Pathway

Periodontitis is a chronic inflammatory disease closely associated with reactive oxygen species (ROS) involvement. Eliminating ROS to control the periodontal microenvironment and alleviate the inflammatory response could potentially serve as an efficacious therapy for periodontitis. Melatonin (MT), renowned for its potent antioxidant and anti-inflammatory characteristics, is frequently employed as an ROS scavenger in inflammatory diseases. However, the therapeutic efficacy of MT remains unsatisfactory due to the low water solubility and poor bioavailability. Carbon dots have emerged as a promising and innovative nanomaterial with facile synthesis, environmental friendliness, and low cost. In this study, melatonin-derived carbon dots (MT-CDs) were successfully synthesized via the hydrothermal method. The MT-CDs have good water solubility and biocompatibility and feature excellent ROS-scavenging capacity without additional modification. The in vitro experiments proved that MT-CDs efficiently regulated intracellular ROS, which maintained mitochondrial homeostasis and suppressed the production of inflammatory mediators. Furthermore, findings from the mouse model of periodontitis indicated that MT-CDs significantly inhibited the deterioration of alveolar bone and reduced osteoclast activation and inflammation, thereby contributing to the regeneration of damaged tissue. In terms of the mechanism, MT-CDs may scavenge ROS, thereby preventing cellular damage and the production of inflammatory factors by regulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. The findings will offer a vital understanding of the advancement of secure and effective ROS-scavenging platforms for more biomedical applications.

Dual-Functional Injectable Hydrogel for Osteoarthritis Treatments

Osteoarthritis (OA) is a prevalent, chronic degenerative disease that affects people worldwide. It is characterized by the destruction of cartilage and inflammatory reactions. High levels of reactive oxygen species (ROS) cause oxidative stress, which damages lipids, proteins, and DNA, leading to cell damage and death. Furthermore, ROS also induces the production of inflammatory cytokines and cell chemotaxis, further worsening the inflammatory response and damaging cartilage resulted in limited movement. Herein, this work reports a dual-functional injectable hydrogel, which can help inhibit inflammation by scavenging ROS and provide lubrication to reduce wear and tear on the joints. To create the hydrogel, 3-aminophenylboronic acid modified hyaluronic acid is synthesized, then which is crosslinked with hydroxyl-containing polyvinyl alcohol (PVA) to construct a dual dynamic covalent crosslinked hydrogel oHA-PBA-PVA gel, Gel (HPP). The hydrogel mentioned here possesses a unique bond structure that allows it to be injected, self-heal, and provide lubrication. This innovative approach offers a new possibility for treating osteoarthritis by combining anti-inflammatory and lubrication effects.

[Research Progress in the Molecular Regulatory Mechanisms of Alveolar Bone Restoration]

Alveolar bone, the protruding portion of the maxilla and the mandible that surrounds the roots of teeth, plays an important role in tooth development, eruption, and masticatory performance. In oral inflammatory diseases, including apical periodontitis, periodontitis, and peri-implantitis, alveolar bone defects cause the loosening or loss of teeth, impair the masticatory function, and endanger the physical and mental health of patients. However, alveolar bone restoration is confronted with great clinical challenges due to the the complicated effect of the biological, mechanical, and chemical factors in the oral microenvironment. An in-depth understanding of the underlying molecular regulatory mechanisms will contribute to the exploration of new targets for alveolar bone restoration. Recent studies have shown that Notch, Wnt, Toll-like receptor (TLR), and nuclear factor-κB (NF-κB) signaling pathways regulate the proliferation, differentiation, apoptosis, and autophagy of osteoclasts, osteoblasts, osteocytes, periodontal ligament cells, macrophages, and adaptive immune cells, modulate the expression of inflammatory mediators, affect the balance of the receptor activator for nuclear factor-κB ligand/receptor activator for nuclear factor-κB/osteoprotegerin (RANKL/RANK/OPG) system, and ultimately participate in alveolar bone restoration. Additionally, alveolar bone restoration involves AMP-activated protein kinase (AMPK), phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT), Hippo/YAP, Janus kinase/signal transducer and activator of transcription (JAK/STAT), and transforming growth factor β (TGF-β) signaling pathways. However, current studies have failed to construct mature molecular regulatory networks for alveolar bone restoration. There is an urgent need for further research on the molecular regulatory mechanisms of alveolar bone restoration by using new technologies such as single-cell transcriptome sequencing and spatial transcriptome sequencing.

New insights into nanotherapeutics for periodontitis: a triple concerto of antimicrobial activity, immunomodulation and periodontium regeneration

Periodontitis is a chronic inflammatory disease caused by the local microbiome and the host immune response, resulting in periodontal structure damage and even tooth loss. Scaling and root planning combined with antibiotics are the conventional means of nonsurgical treatment of periodontitis, but they are insufficient to fully heal periodontitis due to intractable bacterial attachment and drug resistance. Novel and effective therapeutic options in clinical drug therapy remain scarce. Nanotherapeutics achieve stable cell targeting, oral retention and smart release by great flexibility in changing the chemical composition or physical characteristics of nanoparticles. Meanwhile, the protectiveness and high surface area to volume ratio of nanoparticles enable high drug loading, ensuring a remarkable therapeutic efficacy. Currently, the combination of advanced nanoparticles and novel therapeutic strategies is the most active research area in periodontitis treatment. In this review, we first introduce the pathogenesis of periodontitis, and then summarize the state-of-the-art nanotherapeutic strategies based on the triple concerto of antibacterial activity, immunomodulation and periodontium regeneration, particularly focusing on the therapeutic mechanism and ingenious design of nanomedicines. Finally, the challenges and prospects of nano therapy for periodontitis are discussed from the perspective of current treatment problems and future development trends.

Metronidazole-loaded polydopamine nanomedicine with antioxidant and antibacterial bioactivity for periodontitis

Aim: This study focused on treating periodontitis with bacterial infection and local over accumulation of reactive oxygen species. Materials & methods: Polydopamine nanoparticles (PDA NPs) were exploited as efficient carriers for encapsulated metronidazole (MNZ). The therapeutic efficacy and biocompatibility of PDA@MNZ NPs were investigated through both in vitro and in vivo studies. Results: The nanodrug PDA@MNZ NPs were successfully fabricated, with well-defined physicochemical characteristics. In vitro, the PDA@MNZ NPs effectively eliminated intracellular reactive oxygen species and inhibited the growth of Porphyromonas gingivalis. Moreover, the PDA@MNZ NPs exhibited synergistic therapy for periodontitisin in vivo. Conclusion: PDA@MNZ NPs were confirmed with exceptional antimicrobial and antioxidant functions, offering a promising avenue for synergistic therapy in periodontitis.

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.

Salivary Oxidative Stress Biomarkers in Thai Adolescents and Young Adults with Type 1 Diabetes Mellitus: A Cross-Sectional Study

Aims and Objectives

The primary objectives of this study were to compare salivary oxidative stress (OS) biomarker levels in patients with type 1 diabetes mellitus (T1DM) and without T1DM (non-T1DM) and evaluate the relationships between diabetes, periodontal status, and OS biomarker levels.

Materials and Methods

Twenty patients with T1DM and 20 age-matched patients without T1DM were enrolled. All participants were 15-23 years of age and had permanent dentition. Unstimulated whole saliva was collected in a sterile test tube before examination of clinical periodontal parameters, including bleeding on probing (BOP). Salivary levels of OS biomarkers-malondialdehyde, protein carbonyl, total oxidant status (TOS), and total antioxidant capacity-were determined using oxidative and antioxidative assays followed by spectrophotometric measurement at 375-532 nm. The relationships between diabetes, periodontal status, and OS biomarkers were analyzed using multiple linear regression.

Results

TOS was significantly lower in the T1DM group compared with the non-T1DM group (5.06 ± 0.39 vs. 6.44 ± 0.51 µmol H2O2 Eq/l, P = 0.035). After adjusting for confounding factors (age, gender, BMI, clinical periodontal parameters, BOP, or diabetes status accordingly), the multiple linear regression showed that T1DM was significantly associated with a reduction of TOS level (P = 0.008). The BOP > 30% group showed a significant correlation with increased TOS levels compared with the BOP ≤ 30% group (P = 0.002). No relationship was found between OS biomarkers and HbA1c levels.

Conclusion

Salivary TOS levels were related to both diabetes status and the extent of gingival inflammation. Further studies to elucidate the role of OS in relation of periodontal disease and T1DM are required.

Curcumin Attenuates Periodontal Injury via Inhibiting Ferroptosis of Ligature-Induced Periodontitis in Mice

Periodontitis is a chronic infectious disease characterized by the destruction of connective tissue and alveolar bone that eventually leads to tooth loss. Ferroptosis is an iron-dependent regulated cell death and is involved in ligature-induced periodontitis in vivo. Studies have demonstrated that curcumin has a potential therapeutic effect on periodontitis, but the mechanism is still unclear. The purpose of this study was to investigate the protective effects of curcumin on alleviating ferroptosis in periodontitis. Ligature-induced periodontal-diseased mice were used to detect the protective effect of curcumin. The level of superoxide dismutase (SOD), malondialdehyde (MDA) and total glutathione (GSH) in gingiva and alveolar bone were assayed. Furthermore, the mRNA expression levels of acsl4, slc7a11, gpx4 and tfr1 were measured using qPCR and the protein expression of ACSL4, SLC7A11, GPX4 and TfR1 were investigated by Western blot and immunocytochemistry (IHC). Curcumin reduced the level of MDA and increased the level of GSH. Additionally, curcumin was proven to significantly increase the expression levels of SLC7A11 and GPX4 and inhibit the expression of ACSL4 and TfR1. In conclusion, curcumin plays a protective role by inhibiting ferroptosis in ligature-induced periodontal-diseased mice.

Engineering ROS-scavenging Prussian blue nanozymes for efficient atherosclerosis nanotherapy

Atherosclerosis (AS), characterized by a chronic inflammatory disease, is a top cause of morbidity and disability worldwide. During the pathogenesis of AS, the leading process of inflammation highly involves a secondary event of oxidative stress, but limited antioxidants are currently available clinically due to their nonspecific effects, poor biosafety, and rapid in vivo elimination and urinary excretion as well as short retention time within plaque lesions. In this work, Prussian blue nanozymes with a strong reactive oxygen species (ROS)-scavenging ability were rationally engineered for efficient AS nanotherapy. Specifically, the obtained nanozymes with high photothermal performance could behave as potent photoacoustic imaging agents for plaque detection. In addition, these nanozymes featuring multienzyme activities could reduce the cellular ROS level, exert cytoprotective effects against ROS-mediated macrophages apoptosis, and inhibit foam cell formation, significantly boycotting AS development. The underlying mechanism was further verified by transcriptome sequencing at the cellular level and a series of immunohistochemical staining of aortic sinus sections in apoE^-/- mice. Finally, the high biocompatibility and biosafety of the engineered Prussian blue nanozymes further guarantee their clinical translation potential for AS management.

Anti-Periodontitis Effects of Dendropanax morbiferus H.Lév Leaf Extract on Ligature-Induced Periodontitis in Rats

Periodontitis is caused by pathogens in the oral cavity. It is a chronic infectious disease that causes symptoms including gingival bleeding and tooth loss resulting from the destruction of periodontal tissues coupled with inflammation. Dendropanax morbiferus H.Lév (DM) is a natural product that exhibits various biological activities with few side effects. In this study, the potential of DM leaf hot-water extracts (DMWE) as a treatment for periodontitis was determined and its anti-oxidant and anti-inflammatory effects were evaluated. Compounds in DMWE were identified by high-performance liquid chromatography (HPLC) and nitric oxide (NO) and prostaglandin E₂ (PGE₂) production was measured in RAW 264.7 cells. We measured the gingival index and gingival sulcus depth, and micro-CT was performed in vivo using a ligature-induced periodontitis rat model, which is similar to human periodontitis. The DMWE-treated group exhibited a decrease in cytokine concentration and relieved the gingival index and gingival sulcus depth compared with the periodontitis-induced control group. In addition, micro-CT and histological analysis revealed that DMWE exhibited anti-inflammatory effects and improved alveolar bone loss in periodontitis-induced rats. These findings suggest that DMWE has excellent anti-oxidant and anti-inflammatory effects that protect and prevent periodontal tissue damage and tooth loss caused by the inflammatory response.