Cascade and Ultrafast Artificial Antioxidases Alleviate Inflammation and Bone Resorption in Periodontitis

Gold Nanoparticles Confined in Mesoporous Bioactive Glass for Periodontitis Therapy

Periodontitis is a chronic disease caused by bacterial infection and is characterized with alveolar bone resorption. Bone regeneration in periodontitis remains a critical challenge because bacterial infection induced an unfavorable microenvironment for osteogenesis. Therefore, it is necessary to design proper therapeutic platforms to control bacterial infection and promote bone regeneration. Herein, mesoporous bioactive glass (MBG) with different pore sizes (3.0, 4.3, and 12.3 nm) was used as an in situ reactor to confine the growth of gold nanoparticles (Au NPs), forming MBG@Au hybrids which combine the osteoconductivity of MBG and antibacterial properties of Au NPs. Upon near-infrared (NIR) irradiation, the MBG@Au NPs showed efficient antibacterial properties both in vitro and in vivo. Besides, the osteogenesis properties of MBG@Au also improved under NIR irradiation. Furthermore, the in vivo results demonstrated that MBG@Au can effectively promote alveolar bone regeneration and realize the healing of serious periodontitis.

Artificial Phages with Biocatalytic Spikes for Synergistically Eradicating Antibiotic-Resistant Biofilms

Antibiotic-resistant pathogens have become a global public health crisis, especially biofilm-induced refractory infections. Efficient, safe, and biofilm microenvironment (BME)-adaptive therapeutic strategies are urgently demanded to combat antibiotic-resistant biofilms. Here, inspired by the fascinating biological structures and functions of phages, the de novo design of a spiky Ir@Co3O4 particle is proposed to serve as an artificial phage for synergistically eradicating antibiotic-resistant Staphylococcus aureus biofilms. Benefiting from the abundant nanospikes and highly active Ir sites, the synthesized artificial phage can simultaneously achieve efficient biofilm accumulation, extracellular polymeric substance (EPS) penetration, and superior BME-adaptive reactive oxygen species (ROS) generation, thus facilitating the in situ ROS delivery and enhancing the biofilm eradication. Moreover, metabolomics found that the artificial phage obstructs the bacterial attachment to EPS, disrupts the maintenance of the BME, and fosters the dispersion and eradication of biofilms by down-regulating the associated genes for the biosynthesis and preservation of both intra- and extracellular environments. The in vivo results demonstrate that the artificial phage can treat the biofilm-induced recalcitrant infected wounds equivalent to vancomycin. It is suggested that the design of this spiky artificial phage with synergistic "penetrate and eradicate" capability to treat antibiotic-resistant biofilms offers a new pathway for bionic and nonantibiotic disinfection.

Development of an injectable oxidized dextran/gelatin hydrogel capable of promoting the healing of alkali burn-associated corneal wounds

The cornea serves as an essential shield that protects the underlying eye from external conditions, yet it remains highly vulnerable to injuries that could lead to blindness and scarring if not promptly and effectively treated. Excessive inflammatory response constitute the primary cause of pathological corneal injury. This study aimed to develop effective approaches for enabling the functional repair of corneal injuries by combining nanoparticles loaded with anti-inflammatory agents and an injectable oxidized dextran/gelatin/borax hydrogel. The injectability and self-healing properties of developed hydrogels based on borate ester bonds and dynamic Schiff base bonds were excellent, improving the retention of administered drugs on the ocular surface. In vitro cellular assays and in vivo animal studies collectively substantiated the proficiency of probucol nanoparticle-loaded hydrogels to readily suppress proinflammatory marker expression and to induce the upregulation of anti-inflammatory mediators, thereby supporting rapid repair of rat corneal tissue following alkali burn-induced injury. As such, probucol nanoparticle-loaded hydrogels represent a prospective avenue to developing long-acting and efficacious therapies for ophthalmic diseases.

Polyphenols-based intelligent oral barrier membranes for periodontal bone defect reconstruction

Periodontitis-induced periodontal bone defects significantly impact patients' daily lives. The guided tissue regeneration and guided bone regeneration techniques, which are based on barrier membranes, have brought hope for the regeneration of periodontal bone defects. However, traditional barrier membranes lack antimicrobial properties and cannot effectively regulate the complex oxidative stress microenvironment in periodontal bone defect areas, leading to unsatisfactory outcomes in promoting periodontal bone regeneration. To address these issues, our study selected the collagen barrier membrane as the substrate material and synthesized a novel barrier membrane (PO/4-BPBA/Mino@COL, PBMC) with an intelligent antimicrobial coating through a simple layer-by-layer assembly method, incorporating reactive oxygen species (ROS)-scavenging components, commercial dual-functional linkers and antimicrobial building blocks. Experimental results indicated that PBMC exhibited good degradability, hydrophilicity and ROS-responsiveness, allowing for the slow and controlled release of antimicrobial drugs. The outstanding antibacterial, antioxidant and biocompatibility properties of PBMC contributed to resistance to periodontal pathogen infection and regulation of the oxidative balance, while enhancing the migration and osteogenic differentiation of human periodontal ligament stem cells. Finally, using a rat periodontal bone defect model, the therapeutic effect of PBMC in promoting periodontal bone regeneration under infection conditions was confirmed. In summary, the novel barrier membranes designed in this study have significant potential for clinical application and provide a reference for the design of future periodontal regenerative functional materials.

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.

Cuttlefish-Inspired Photo-Responsive Antibacterial Microparticles with Natural Melanin Nanoparticles Spray

Topical antibiotics can be utilized to treat periodontitis, while their delivery stratagems with controlled release and long-lasting bactericidal inhibition are yet challenging. Herein, inspired by the defensive behavior of cuttlefish expelling ink, this work develops innovative thermal-responsive melanin-integrated porous microparticles (MPs) through microfluidic synthesis for periodontitis treatment. These MPs are composed of melanin nanoparticles (NPs), poly(N-isopropylacrylamide) (PNIPAM), and agarose. Benefiting from the excellent biocompatibility and large surface area ratio of MPs, they can deliver abundant melanin NPs. Under near-infrared irradiation, the melanin NPs can convert photo energy into thermal energy. This leads to agarose melting and subsequent shrinkage of the microspheres induced by pNIPAM, thereby facilitating the release of melanin NPs. In addition, the released melanin NPs can serve as a highly effective photothermal agent, displaying potent antibacterial activity against porphyromonas gingivalis and possessing natural anti-inflammatory properties. These unique characteristics are further demonstrated through in vivo experiments, showing the antibacterial effects in the treatment of infected wounds and periodontitis. Therefore, the catfish-inspired photo-responsive antibacterial MPs with controlled-release drug delivery hold tremendous potential in clinical antibacterial applications.

Diamond-Like Carbon Depositing on the Surface of Polylactide Membrane for Prevention of Adhesion Formation During Tendon Repair

Post-traumatic peritendinous adhesion presents a significant challenge in clinical medicine. This study proposes the use of diamond-like carbon (DLC) deposited on polylactic acid (PLA) membranes as a biophysical mechanism for anti-adhesion barrier to encase ruptured tendons in tendon-injured rats. The results indicate that PLA/DLC composite membrane exhibits more efficient anti-adhesion effect than PLA membrane, with histological score decreasing from 3.12 ± 0.27 to 2.20 ± 0.22 and anti-adhesion effectiveness increasing from 21.61% to 44.72%. Mechanistically, the abundant C=O bond functional groups on the surface of DLC can reduce reactive oxygen species level effectively; thus, the phosphorylation of NF-κB and M1 polarization of macrophages are inhibited. Consequently, excessive inflammatory response augmented by M1 macrophage-originated cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) is largely reduced. For biocompatibility evaluation, PLA/DLC membrane is slowly absorbed within tissue and displays prolonged barrier effects compared to traditional PLA membranes. Further studies show the DLC depositing decelerates the release of degradation product lactic acid and its induction of macrophage M2 polarization by interfering esterase and PLA ester bonds, which further delays the fibrosis process. It was found that the PLA/DLC membrane possess an efficient biophysical mechanism for treatment of peritendinous adhesion.

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.

Photo-crosslinked integrated triphasic scaffolds with gradient composition and strength for osteochondral regeneration

Owing to the avascular and aneural nature of cartilage tissue and the complex, multilayered structure of osteochondral units, the repair of osteochondral defects poses significant challenges. Traditional monophasic scaffolds have difficulty meeting the repair requirements of both cartilage and bone tissues, whereas multiphasic scaffolds face the issue of interfacial integration. In this study, a triphasic methylpropenylated gelatin (GELMA) hydrogel scaffold was employed to repair osteochondral defects, in which three layers of hydrogel were covalently bonded through a sequential curing process. The upper layer of the scaffold was covalently bonded with chondroitin sulfate, promoting chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The middle and lower layers of the hydrogel introduced a gradient content of hydroxyapatite, forming a scaffold with gradient mechanical strength and effectively enhancing its angiogenic and osteogenic induction capabilities. Finally, the triphasic integrated scaffold cartilage and bone repair performance was evaluated using a rabbit knee joint defect model. The results demonstrated that the scaffold facilitated accelerated regeneration of osteochondral defects, thus providing a novel strategy for the treatment of osteochondral defects.

Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating Microenvironment and Alleviating Solar Dermatitis

Solar dermatitis, a form of acute radiation burn that affects the skin, results from overexposure to ultraviolet B (UVB) radiation in strong sunlight. Cell damage caused by the accumulation of reactive oxygen species (ROS) produced by UVB radiation plays an important role in UVB-induced inflammation in the skin. Here, for efficiently scavenging excess ROS, modulating the microenvironment, and alleviating solar dermatitis, a π-conjugated network polyphthalocyanine supporting a highly surface-exposed Ru active site-based artificial antioxidase (HSE-PPcRu) is designed and fabricated with excellent ROS-scavenging, antioxidant, and anti-inflammatory capabilities. In photodamaged human keratinocyte cells, HSE-PPcRu could modulate mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B signaling pathways, prevent DNA damage, suppress apoptosis, inhibit pro-inflammatory cytokine secretion, and alleviate cell damage. In vivo animal experiments reveal the higher antioxidant and anti-inflammatory efficacies of HSE-PPcRu by reversing the activation of p38 and c-Jun N-terminal kinase, inhibiting expression of cyclooxygenase-2, interleukin-6, interleukin-8, and tumor necrosis factor-α. This work not only provides an idea for alleviating solar dermatitis via catalytically scavenging ROS and modulating the microenvironment but also offers a strategy to design an intelligent conjugated network-based artificial antioxidase with a highly surface-exposed active site.

Ceria Nanozyme Coordination with Curcumin for Treatment of Sepsis-induced Cardiac Injury by Inhibiting Ferroptosis and Inflammation

INTRODUCTION

Sepsis-induced cardiac injury is the leading cause of death in patients. Recent studies have reported that reactive oxygen species (ROS)-mediated ferroptosis and macrophage-induced inflammation are the two main key roles in the process of cardiac injury. The combination of ferroptosis and inflammation inhibition is a feasible strategy in the treatment of sepsis-induced cardiac injury.

OBJECTIVES

In the present study, ceria nanozyme coordination with curcumin (CeCH) was designed by a self-assembled method with human serum albumin (HSA) to inhibit ferroptosis and inflammation of sepsis-induced cardiac injury.

METHODS AND RESULTS

The formed CeCH obtained the superoxide dismutase (SOD)-like and catalase (CAT)-like activities from ceria nanozyme to scavenge ROS, which showed a protective effect on cardiomyocytes in vitro. Furthermore, it also showed ferroptosis inhibition to reverse cell death from RSL3-induced cardiomyocytes, denoted from curcumin. Due to the combination therapy of ceria nanozyme and curcumin, the formed CeCH NPs could also promote M2 macrophage polarization to reduce inflammation in vitro. In the lipopolysaccharide (LPS)-induced sepsis model, the CeCH NPs could effectively inhibit ferroptosis, reverse inflammation, and reduce the release of pro-inflammatory factors, which markedly alleviated the myocardial injury and recover the cardiac function.

CONCLUSION

Overall, the simple self-assembled strategy with ceria nanozyme and curcumin showed a promising clinical application for sepsis-induced cardiac injury by inhibiting ferroptosis and inflammation.

Acknowledgments

This study was supported by grants of the National Natural Science Foundation of China (82100398); the Nanjing Medical Science and Technique Development Foundation (YKK21068); Clinical Trials from the Affiliated Drum Tower Hospital, Medical School of Nanjing University (2023-LCYJ-PY-24); the Jiangsu Research Hospital Association for Precision Medication (JY202120); the Jiangsu Pharmaceutical Association for Jinpeiying Project (J2021001); China Postdoctoral Science Foundation (2022M721576).

Reactive oxygen nanobiocatalysts: activity-mechanism disclosures, catalytic center evolutions, and changing states

Benefiting from low costs, structural diversities, tunable catalytic activities, feasible modifications, and high stability compared to the natural enzymes, reactive oxygen nanobiocatalysts (RONBCs) have become dominant materials in catalyzing and mediating reactive oxygen species (ROS) for diverse biomedical and biological applications. Decoding the catalytic mechanism and structure-reactivity relationship of RONBCs is critical to guide their future developments. Here, this timely review comprehensively summarizes the recent breakthroughs and future trends in creating and decoding RONBCs. First, the fundamental classification, activity, detection method, and reaction mechanism for biocatalytic ROS generation and elimination have been systematically disclosed. Then, the merits, modulation strategies, structure evolutions, and state-of-art characterisation techniques for designing RONBCs have been briefly outlined. Thereafter, we thoroughly discuss different RONBCs based on the reported major material species, including metal compounds, carbon nanostructures, and organic networks. In particular, we offer particular insights into the coordination microenvironments, bond interactions, reaction pathways, and performance comparisons to disclose the structure-reactivity relationships and mechanisms. In the end, the future challenge and perspectives for RONBCs are also carefully summarised. We envision that this review will provide a comprehensive understanding and guidance for designing ROS-catalytic materials and stimulate the wide utilisation of RONBCs in diverse biomedical and biological applications.