Cu-GA-coordination polymer nanozymes with triple enzymatic activity for wound disinfection and accelerated wound healing

Magnesium Ion/Gallic Acid MOF-Laden Multifunctional Acellular Matrix Hydrogels for Diabetic Wound Healing

The main objective for diabetic wound treatment is the design of a functional dressing that scavenges free radicals, alleviates inflammation, and is antibacterial while promoting neovascularization. Herein, a multifunctional acellular matrix hydrogel was prepared with the antimicrobial peptide jelleine-1 and a magnesium ion/gallic acid metal framework to exhibit antioxidant, anti-inflammatory, and proangiogenesis effects in diabetic wounds. The prepared hydrogel termed Gel-J-MOF efficiently released gallic acid in the acidic microenvironment of the diabetic wound, scavenged excess free radicals in vitro, and effectively reduced the levels of inflammation by regulating M2 macrophage polarization in vivo. The antimicrobial peptide jelleine-1 in the composite hydrogel effectively inhibited S. aureus and E. coli in vitro, promoting a suitable microenvironment for wound healing. In the later stage of wound healing, the composite hydrogel stimulated angiogenesis, accelerating the re-epithelialization and collagen deposition in the wound. In conclusion, this multifunctional composite hydrogel provides a regulated microenvironment for treating diabetic wounds and, therefore, has significant potential application promise in the treatment of chronic diabetic wounds.

Multifunctional CuTax nanozyme-based chitosan edible coatings for fruit preservation

The preservation of fresh fruits is critically challenged by oxidative degradation and microbial contamination, which lead to quality deterioration and reduced shelf life. In this study, we took advantage of the multiple benefits of Taxfolin (Tax) and copper to develop CuTax nanozymes, and which were showed to have excellent free radical scavenging ability, as evidenced by 90.3 % ± 0.2 % DPPH and 85.61 % ± 0.08 % ABTS free radical scavenging rates. Additionally, the CuTax exhibited peroxidase-like (POD-like) activity and effective glutathione (GSH) depletion. Moreover, the CuTax were found to effectively suppress the colony formation of E. coli and S. aureus, reduce bacterial viability, and disrupt bacterial structures. Ultimately, a CuTax/CS composite coating/films for food preservation was successfully developed using chitosan (CS) as a carrier and the protective efficacy against food spoilage was evaluated using bananas and apples as representative fruits. These findings suggest that CuTax/CS composite coatings offer a multifunctional approach to active food packaging that effectively extend the shelf life and preserve the quality of fresh fruits.

AuCu@CuO2 Aerogels with H2O2/O2 Self-Supplying and Quadruple Enzyme-Like Activity for MRSA-Infected Diabetic Wound Management

Diabetic wound healing presents serious clinical challenges due to the unique wound microenvironment characterized by hyperglycemia, bacterial infection, excessive oxidative stress, and hypoxia. Herein, a copper peroxide (CuO2)-coated AuCu bimetallic aerogel is developed that exhibits quadruple enzyme-mimicking activity and H2O2/O2 self-supplying to modulate the complex microenvironment of methicillin-resistant staphylococcus aureus (MRSA)-infected diabetic wounds. The AuCu@CuO2 aerogels demonstrate favorable photothermal properties and mimic four enzyme-like activities: peroxidase-like activity for producing toxic reactive oxygen species; catalase-like activity for decomposing H2O2 to release O2 to relieve oxidative stress and hypoxia; glucose oxidase-like activity for reducing excessive blood glucose and glutathione peroxidase-like activity for balancing abnormal glutathione level. The CuO2 coating facilitates a continuous and adequate in situ production of H2O2 within the mildly acidic infection microenvironment, enabling excellent antibacterial activity and reduced blood glucose levels during the initial treatment of infected diabetic wounds. Furthermore, the engineered AuCu@CuO2 aerogels not only scavenge elevated ROS during the inflammatory phase but also synergistically generate oxygen to promote wound healing. Overall, the AuCu@CuO2 aerogelsmicroenvironment can be activated by the diabetic wound infection microenvironments, alleviating inflammation, reducing hypoxia, lowering blood glucose levels, and enhancing angiogenesis and collagen fiber accumulation, thereby significantly improving diabetic wound healing.

Photothermally Enhanced Cascaded Nanozyme-Functionalized Black Phosphorus Nanosheets for Targeted Treatment of Infected Diabetic Wounds

Due to the limitations of H2O2 under physiological conditions and defective activity, nanozyme-catalyzed therapy for infected diabetic wound healing is still a huge challenge. Here, this work designs a novel multifunctional hybrid glucose oxidase (GOx)-CeO2@black phosphorus (BP)/Apt nanosheet that features GOx and CeO2 dual enzyme loading with photothermal enhancement effect and targeting ability for the treatment of infected wounds in type II diabetic mice. Combined with the photothermal properties of the BP nanosheets, the cascade nanozyme effect of GOx and CeO2 is extremely enhanced. The synergistic effect of peroxidase activity and photothermal therapy with targeting aptamer allows for overcoming the catalytic defects of nanozyme and significantly improving in vitro bacterial inhibition rate with 99.9% and 97.8% for Staphylococcus aureus and Escherichia coli, respectively, as well as enhancing in vivo antibacterial performance with the lowest wound remained (0.05%), reduction of infiltration inflammatory cells, and excellent biocompatibility. Overall, this work builds a nanodelivery system with a powerful therapeutic approach, incorporating self-supplying H2O2 synergistic photothermal and real-time wound monitoring effect, which holds profound potential as a clinical treatment for infected diabetic wounds.

Nanotherapies Based on ROS Regulation in Oral Diseases

Oral diseases rank among the most prevalent clinical conditions globally, typically involving detrimental factors such as infection, inflammation, and injury in their occurrence, development, and outcomes. The concentration of reactive oxygen species (ROS) within cells has been demonstrated as a pivotal player in modulating these intricate pathological processes, exerting significant roles in restoring oral functionality and maintaining tissue structural integrity. Due to their enzyme-like catalytic properties, unique composition, and intelligent design, ROS-based nanomaterials have garnered considerable attention in oral nanomedicine. Such nanomaterials have the capacity to influence the spatiotemporal dynamics of ROS within biological systems, guiding the evolution of intra-ROS to facilitate therapeutic interventions. This paper reviews the latest advancements in the design, functional customization, and oral medical applications of ROS-based nanomaterials. Through the analysis of the components and designs of various novel nanozymes and ROS-based nanoplatforms responsive to different stimuli dimensions, it elaborates on their impacts on the dynamic behavior of intra-ROS and their potential regulatory mechanisms within the body. Furthermore, it discusses the prospects and strategies of nanotherapies based on ROS scavenging and generation in oral diseases, offering alternative insights for the design and development of nanomaterials for treating ROS-related conditions.

A glutathione-activated bismuth-gallic acid metal-organic framework nano-prodrug for enhanced sonodynamic therapy of breast tumor

Sonodynamic therapy is a promising, noninvasive, and precise tumor treatment that leverages sonosensitizers to generate cytotoxic reactive oxygen species during ultrasound stimulation. Gallic acid (GA), a natural polyphenol, possesses certain anti-tumor properties, but exhibits significant toxicity toward normal cells, limiting its application in cancer treatment. To overcome this issue, we synthesized a bismuth-gallic acid (BGA), coordinated metal-organic framework (MOF) nano-prodrug. Upon encountering glutathione (GSH), BGA gradually dissociated and depleted GSH, releasing GA, which had anti-tumor effects. As an MOF with semiconductor properties, BGA primarily produced superoxide anion radical upon ultrasound excitation. After the release of GA, GA generated superoxide anion radical and further produced high toxic singlet oxygen under ultrasound stimulation, while further oxidizing and consuming GSH, enhancing sonocatalytic performance. Additionally, the released GA induced cell cycle arrest, ultimately leading to apoptosis. Our results revealed that BGA, as a GSH-activated, metal-polyphenol MOF nano-prodrug, showed potential for use in breast tumor sonodynamic therapy, providing a novel strategy for precise tumor treatment.

Copper-Based Nanozymes: Potential Therapies for Infectious Wounds

Bacterial infections are a significant obstacle to the healing of acute and chronic wounds, such as diabetic ulcers and burn injuries. Traditional antibiotics are the primary treatment for bacterial infections, but they present issues such as antibiotic resistance, limited efficacy, and potential side effects. This challenge leads to the exploration of nanozymes as alternative therapeutic agents. Nanozymes are nanomaterials with enzyme-like activities. Owing to their low production costs, high stability, scalability, and multifunctionality, nanozymes have emerged as a prominent focus in antimicrobial research. Among various types of nanozymes, metal-based nanozymes offer several benefits, including broad-spectrum antimicrobial activity and robust catalytic properties. Specifically, copper-based nanozymes (CuNZs) have shown considerable potential in promoting wound healing. They exhibit strong antimicrobial effects, reduce inflammation, and enhance tissue regeneration, making them highly advantageous for use in wound care. This review describes the dual functions of CuNZs in combating infection and facilitating wound repair. Recent advancements in the design and synthesis of CuNZs, evaluating their antimicrobial efficacy, healing promotion, and biosafety both in vitro and in vivo on the basis of their core components, are critically important.

ZnO‐CuS/F127 Hydrogels with Multienzyme Properties for Implant‐Related Infection Therapy by Inhibiting Bacterial Arginine Biosynthesis and Promoting Tissue Repair

Implant‐related infections are characterized by the formation of bacterial biofilms. Current treatments have various drawbacks. Nanozymes with enzyme‐like activity can produce highly toxic substances to kill bacteria and remove biofilms without inducing drug resistance. However, it is difficult for current monometallic nanozymes to function well in complex biofilm environments. Therefore, the development of multimetallic nanozymes with efficient multienzyme activities is crucial. In the present study, bimetallic nanozyme, ZnO‐CuS nanoflowers with peroxidase (POD), glutathione oxidase (GSH‐Px), and catalase (CAT) activity are successfully synthesized via calcination and loaded into F127 hydrogels for the treatment of implant‐related infections. The ability of ZnO‐CuS nanoflowers to bind bacteria is key for efficient antimicrobial activity. In addition, ZnO‐CuS nanoflowers with H2O2 disrupt the metabolism of MRSA, including arginine synthesis, nucleotide excision repair, energy metabolism, and protein synthesis. ZnO‐CuS/F127 hydrogel in combination with H2O2 has been demonstrated to be effective in clearing biofilm infection and facilitating the switch of M1 macrophages to M2‐repairative phenotype macrophages for the treatment of implant infections in mice. Furthermore, ZnO‐CuS/F127 hydrogels have favorable biosafety, and their toxicity is negligible. ZnO‐CuS/F127 hydrogel has provided a promising biomedical strategy for the healing of implant‐related infections, highlighting the potential of bimetallic nanozymes for clinical applications.

Shenling Baizhu San improves spermatogenic dysfunction in hyperuricemia mice by regulating Sirt3/Nrf2 to inhibit testicular ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

The effect of hyperuricemia (HUA) on testicular spermatogenesis cannot be ignored. The classical Chinese medicine compound Shenling Baizhu San (SLBZS) can reduce uric acid and improve testicular spermatogenesis, while researchers have not well explored the related pathology and pharmacodynamic mechanism have.

AIMS OF STUDY

To investigate whether the dysfunction of testicular spermatogenesis caused by HUA and the therapeutic effect of SLBZS are related to testicular cell ferroptosis.

MATERIALS AND METHODS

C57BL/6 mice and C57BL/6 background Sirt3-/- mice were induced by oxazinate potassium (OXO), and HUA spermatogenic dysfunction mice model were constructed and treated with SLBZS. Sperm quality detection and testicular histopathology served for evaluating the protective mechanism of SLBZS against testicular spermatogenesis in HUA mice. Biochemical detection, transmission electron microscopy, immunohistochemistry and immunofluorescence were used to evaluate ferroptosis level of testicular cells. Western blot analysis assisted in verifying the expression of the corresponding pathway proteins.

RESULTS

The testes of mice with HUA spermatogenic dysfunction were subjected to OXO-induced oxidative stress and ferroptosis, and the Sirt3/Nrf2 pathway-related protein expressions were changed. SLBZS improved the testes of mice with HUA spermatogenic dysfunction in terms of their spermatogenic function, oxidative stress and ferroptosis, and promoted Sirt3/Nrf2 antioxidant pathway-related proteins to be expressed. The analysis of Sirt3-/- mice was modeled and dosed, and it was found that SLBZS could not improve the spermatogenic function, oxidative stress and ferroptosis of Sirt3-deficient model mice' testes.

CONCLUSIONS

OXO-induced spermatogenic dysfunction in HUA is associated with ferroptosis of testicular cells. SLBZS can be used for treating spermatogenic dysfunction in HUA possibly by activating Sirt3/Nrf2 signaling pathway, which inhibits ferroptosis due to oxidative stress.

CaGA nanozymes with multienzyme activity realize multifunctional repair of acute wounds by alleviating oxidative stress and inhibiting cell apoptosis

Acute wounds result from damage to the skin barrier, exposing underlying tissues and increasing susceptibility to bacterial and other pathogen infections. Improper wound care increases the risk of exposure and infection, often leading to chronic nonhealing wounds, which cause significant patient suffering. Early wound repair can effectively prevent the development of chronic nonhealing wounds. In this study, Ca-Gallic Acid (CaGA) nanozymes with multienzyme catalytic activity were constructed for treating acute wounds by coordinating Ca ions with gallic acid. CaGA nanozymes exhibit high superoxide dismutase/catalase (SOD/CAT) catalytic activity and good antioxidant performance in vitro. In vitro experiments demonstrated that CaGA nanozymes can effectively promote cell migration, efficiently scavenge ROS, maintain mitochondrial homeostasis, reduce inflammation, and decrease cell apoptosis. In vivo, CaGA nanozymes promoted granulation tissue formation, accelerated collagen fiber deposition, and reconstructed skin appendages, thereby accelerating acute wound healing. CaGA nanozymes have potential clinical application value in wound healing treatment.

Chiral nanoenzymes: synthesis and applications

Chiral nanoenzymes are a new type of material that possesses both chiral nanostructures and enzymatic catalytic activity. These materials exhibit selectivity in their catalytic activity towards organisms due to the introduction of chiral features in nanomaterials and have inherent chiral discrimination in organisms. As synthetic enzymes, chiral nanoenzymes offer significant advantages over natural enzymes. Due to their unique chiral structure and distinctive physicochemical properties, chiral nanoenzymes play an important role in various fields, including biology, medicine, and environmental protection. Their strong stereospecificity and biocompatibility make them useful in disease therapy, biosensing, and chiral catalysis, setting them apart from conventional and natural enzymes. In recent years, the design of synthetic methods and biological applications of chiral nanoenzymes has received significant attention and extensive research among scientists. This paper provides a systematic review of the research progress in the discovery, development, and application of chiral nanoenzymes in the last decade. Additionally, it presents various applications of chiral nanoenzymes, such as disease therapy, biosensing, and chiral catalysis. Finally, the challenges and future prospects of chiral nanoenzymes are discussed.

Emerging nanozyme therapy incorporated into dental materials for diverse oral pathologies

OBJECTIVE

Nanozyme materials combine the advantages of natural enzymes and artificial catalysis, and have been widely applied in new technologies for dental materials and oral disease treatment. Based on the role of reactive oxygen species (ROS) and oxidative stress pathways in the occurrence and therapy of oral diseases, a comprehensive review was conducted on the methods and mechanisms of nanozymes and their dental materials in treating different oral diseases.

METHODS

This review is based on literature surveys from PubMed and Web of Science databases, as well as reviews of relevant researches and publications on nanozymes in the therapy of oral diseases and oral tumors in international peer-reviewed journals.

RESULTS

Given the unique function of nanozymes in the generation and elimination of ROS, they play an important role in the occurrence, development, and treatment of different oral diseases. The application of nanozymes in dental materials and oral disease treatment was introduced, including the latest advances in their use for dental caries, pulpitis, jaw osteomyelitis, periodontitis, oral mucosal diseases, temporomandibular joint disorders, and oral tumors. Future approaches were also summarized and proposed based on the characteristics of these diseases.

SIGNIFICANCE

This review will guide biomedical researchers and oral clinicians to understand the mechanisms and applications of nanozymes in the therapy of oral diseases, promoting further development in the field of dental materials within the oral medication. It is anticipated that more suitable therapeutic agents or dental materials encapsulating nanozymes, specifically designed for the oral environment and simpler for clinical utilization, will emerge in the forthcoming future.

NH2-MIL-88B@TP-TA@CuS for photothermal catalytic synergistic antibacterial activity

Reactive oxygen species (ROS) provide a promising way to fight bacterial infection and meet the persistent challenge of antibiotic resistance. Nanoenzyme mimics natural enzyme and becomes an effective regulator of ROS level. In this study, NH2-MIL-88B with high specific surface area was selected as the core, and the covalent organic skeleton material TP-TA COF was wrapped by "sequential growth" technology. Subsequently, through the second hydrothermal treatment, the inorganic material CuS with excellent photothermal performance was integrated into the outer layer, and the NH2-MIL-88B@TP-TA@CuSX composite nanoenzyme was synthesized. Different from the traditional nano-enzyme, NH2-MIL-88B@TP-TA@CuSX nano-enzyme still has good catalytic effect under neutral conditions (pH=7). In addition, NH2-MIL-88B@TP-TA@CuSX has good near infrared (NIR) absorption rate and high photothermal conversion efficiency (PTCE is 48.7 %), which can be used for photothermal treatment (PTT) of bacteria. Mild photothermal effect can further enhance the enzyme-like catalytic activity of NH2-MIL-88B@TP-TA@CuSX, so that H2O2 can be more efficiently catalyzed to produce a large number of ROS. The experimental results in vitro show that NH2-MIL-88B@TP-TA@CuSX can effectively kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in the presence of laser irradiation and H2O2.

Herbal small molecule-based low/medium internal phase supramolecular gel emulsion for diabetic wound healing

It remains a big challenge to fabricate low / medium internal phase gel emulsion for the safe wound dressing with low stimulation to the skin. Herein, utilizing the self-assembly and gelation of amphiphilic herbal small molecule-glycyrrhizic acid (GA) derived from traditional Chinese medicine, a new type of supramolecular gel emulsion (SGE) with antibacterial activity and low / medium internal phase was proposed. In the SGE, the oil droplets were stabilized by the nanofibers self-assembled from GA, and the SGE was formed by the supramolecular assembly of GA nanofibers in the presence of Pickering emulsions. As a result, under low / medium internal phase (φ = 30-50 %), SGEs could be readily prepared. Antibacterial tests demonstrated that the growth of gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) could be effectively inhibited by the SGE. Additionally, compared to high internal phase SGE, SGE with φ = 50 % displayed lower cytotoxicity and a positive impact on the healing process of infectious diabetic wounds. This work provided a novel approach for constructing low / medium internal phase gel emulsion via herbal small molecule-based supramolecular assembly.

Combinatorial therapeutic enzymes to combat multidrug resistance in bacteria

AIMS

Antibiotic resistance including multidrug resistance (MDR) is a negative symbol to the human health system because it loses the capability to treat infections. Unfortunately, the available antibiotics do not show an effective therapeutic response against bacterial infections. In the situation of global antibiotic unresponsiveness, enzymatic therapy especially in combinatorial form seems an effective approach to control bacterial infection and combat resistance. The article is important because it focuses on combinatorial enzymatic therapy that has multiple properties (effective antibacterial performances, antibiofilm capacity, immunomodulators, targeted actions, synergistic actions, multiple targeting, and resistance-proof properties) and can address antibiotic resistance effectively.

MATERIALS AND METHODS

We searched the related topics with Pubmed, Scopus, and Google Scholar databases and finally 73 relevant papers were reviewed in detail and cited in this article.

KEY FINDINGS

Discusses properties of combinatorial therapeutic enzymes made it an accomplished means over antibiotic therapy. This article discusses the need for combinatorial enzymatic therapy against bacterial infection, its distinguished features, and properties with multi-mechanistic antibacterial action. It discussed the European Medicine Agency and Food and Drug Administration-approved therapeutic enzymes (antibacterial and antibiofilm).

SIGNIFICANCE

This article provided the possible combination of the enzyme that may be used as an antibacterial agent along with limitations and future scope of combinatorial antibacterial enzymatic agents. This article could draw the attention of researchers to combinatorial therapeutic enzymatic molecules as effective and futuristic therapy to overcome the problem of multiple antibiotic resistance in bacteria.

Multifunctional Adaptable Injectable TiN-Based Hydrogels for Antitumor and Antidrug-Resistant Bacterial Therapy

The close relationship between bacteria and tumors has recently attracted increasing attention, and an increasing number of resources are being invested in the research and development of biomedical materials designed for the treatment of both. In this study, prefabricated TiN nanodots (NDs) and Fe(CO)5 nanoparticles are combined into sodium alginate (ALG) hydrogels to create a biomedical material for the topical treatment of breast cancer and subcutaneous abscesses, and a pseudocatalytic hydrogel with intrinsic photothermal and antibacterial activities is synthesized. TiN+Fe(CO)5+ALG hydrogels are used to determine the ability of Fe(CO)5 to promote CO production. Moreover, TiN NDs catalyze the production of reactive oxygen species (ROS) from hydrogen peroxide in tumor microenvironments and exhibit excellent photothermal conversion properties. After local injection of the TiN+Fe(CO)5+ALG hydrogel into subcutaneous tumors and subcutaneous abscesses, and two-zone near-infrared (NIR-II) irradiation, tumor cells and methicillin-resistant Staphylococcus aureus are effectively removed by the hydrogel, the mouse epidermis exhibiting complete recovery within 8 d, indicating that this hydrogel exhibits better antibacterial efficacy than the small-molecule antibiotic penicillin. This study demonstrates the potential of novel hydrogels for antitumor and antimicrobial combination therapy and aims to provide design ideas for the research and development of multifunctional antitumor and antimicrobial drug combinations.

Microenvironment-sensitive nanozymes for tissue regeneration

Tissue defect is one of the significant challenges encountered in clinical practice. Nanomaterials, including nanoparticles, nanofibers, and metal-organic frameworks, have demonstrated an extensive potential in tissue regeneration, offering a promising avenue for future clinical applications. Nonetheless, the intricate landscape of the inflammatory tissue microenvironment has engendered challenges to the efficacy of nanomaterial-based therapies. This quandary has spurred researchers to pivot towards advanced nanotechnological remedies for overcoming these therapeutic constraints. Among these solutions, microenvironment-sensitive nanozymes have emerged as a compelling instrument with the capacity to reshape the tissue microenvironment and enhance the intricate process of tissue regeneration. In this review, we summarize the microenvironmental characteristics of damaged tissues, offer insights into the rationale guiding the design and engineering of microenvironment-sensitive nanozymes, and explore the underlying mechanisms that underpin these nanozymes' responsiveness. This analysis includes their roles in orchestrating cellular signaling, modulating immune responses, and promoting the delicate process of tissue remodeling. Furthermore, we discuss the diverse applications of microenvironment-sensitive nanozymes in tissue regeneration, including bone, soft tissue, and cartilage regeneration. Finally, we shed our sights on envisioning the forthcoming milestones in this field, prospecting a future where microenvironment-sensitive nanozymes contribute significantly to the development of tissue regeneration and improved clinical outcomes.

NH2-MXene/OXG nanocomposite hydrogel with efficient photothermal antibacterial activity for potentially removing biofilms

The adhesion of bacteria to the surface leads to formation of biofilms causing numerous infection problems in implanting medical devices or interventional therapy. Traditional treatment for such problems is generally to administrate patients with antibiotics or antifungal agent. Alternatively, devices are taken out of the body to mechanically destroy the biofilm and re-used by surgery. In this study, a straightforward method was developed to remove biofilms using a MXene-based photothermal hydrogel. The hydrogel consists of dynamic crosslinking network formed by Schiff-base reaction between aldehyde-containing xyloglucan (OXG) and amine-containing MXene (NH2-MXene), which showed efficient killing of both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) bacteria upon near-infrared (NIR) laser irradiation. The NH2-MXene/OXG nanocomposite hydrogel showed a high photothermal antibacterial efficiency and stable photothermal conversion, demonstrated by efficient removal of biofilms ex vivo.

Sprayable, thermosensitive hydrogels for promoting wound healing based on hollow, porous and pH-sensitive ZnO microspheres

A solvothermal method and the subsequent heat treatment process were developed to fabricate hollow ZnO particles with hierarchical pores on a large scale. The as-obtained hollow, porous ZnO microspheres with tunable sizes, high specific surface areas, pH sensitivity, antibacterial properties, and high adsorption capacities showed significant advantages for drug delivery. Sprayable hydrogels containing hollow, porous ZnO microspheres and curcumin nanoparticles (CNPs) were prepared to accelerate wound healing. The water-dispersed CNPs promoted both the migration of fibroblasts and angiogenesis and an aqueous solution of Pluronic F127 (a temperature-sensitive phase-change hydrogel material) was shown to be an effective choice for medical dressings. The experimental data suggest that hollow, porous ZnO microspheres can be loaded with additional CNPs to achieve continuous long-term therapeutic effects.

Design of Scaffolds Based on Zinc-Modified Marine Collagen and Bilberry Leaves Extract-Loaded Silica Nanoparticles as Wound Dressings

Purpose

In this study, wound dressings were designed using zinc-modified marine collagen porous scaffold as host for wild bilberry (WB) leaves extract immobilized in functionalized mesoporous silica nanoparticles (MSN). These new composites were developed as an alternative to conventional wound dressings. In addition to the antibacterial activity of classic antibiotics, a polyphenolic extract could act as an antioxidant and/or an anti-inflammatory agent as well.

Methods

Wild bilberry leaves extract was prepared by ultrasound-assisted extraction in ethanol and its properties were evaluated by UV-Vis spectroscopy (radical scavenging activity, total amount of polyphenols, flavonoids, anthocyanins, and condensed tannins). The extract components were identified by HPLC, and the antidiabetic properties of the extract were evaluated via α-glucosidase inhibitory activity. Spherical MSN were modified with propionic acid or proline moieties by post-synthesis method and used as carriers for the WB leaves extract. The textural and structural features of functionalized MSN were assessed by nitrogen adsorption/desorption isotherms, small-angle XRD, SEM, TEM, and FTIR spectroscopy. The composite porous scaffolds were prepared by freeze drying of the zinc-modified collagen suspension containing WB extract loaded silica nanoparticles.

Results

The properties of the new composites demonstrated enhanced properties in terms of thermal stability of the zinc-collagen scaffold, without altering the protein conformation, and stimulation of NCTC fibroblasts mobility. The results of the scratch assay showed contributions of both zinc ions from collagen and the polyphenolic extract incorporated in functionalized silica in the wound healing process. The extract encapsulated in functionalized MSN proved enhanced biological activities compared to the extract alone: better inhibition of P. aeruginosa and S. aureus strains, higher biocompatibility on HaCaT keratinocytes, and anti-inflammatory potential demonstrated by reduced IL-1β and TNF-α levels.

Conclusion

The experimental data shows that the novel composites can be used for the development of effective wound dressings.

Copper selenide nanosheets with photothermal therapy-related properties and multienzyme activity for highly effective eradication of drug resistance

Bacterial infections are among the most significant causes of death in humans. Chronic misuse or uncontrolled use of antibiotics promotes the emergence of multidrug-resistant superbugs that threaten public health through the food chain and cause environmental pollution. Based on the above considerations, copper selenide nanosheets (CuSe NSs) with photothermal therapy (PTT)- and photodynamic therapy (PDT)-related properties have been fabricated. These CuSe NSs possess enhanced PDT-related properties and can convert O2 into highly toxic reactive oxygen species (ROS), which can cause significant oxidative stress and damage to bacteria. In addition, CuSe NSs can efficiently consume glutathione (GSH) at bacterial infection sites, thus further enhancing their sterilization efficacy. In vitro antibacterial experiments with near-infrared (NIR) irradiation have shown that CuSe NSs have excellent photothermal bactericidal properties. These experiments also showed that CuSe NSs exerted excellent bactericidal effects on wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) and significantly promoted the healing of infected wounds. Because of their superior biological safety, CuSe NSs are novel copper-based antimicrobial agents that are expected to enter clinical trials, serving as a modern approach to the major problem of treating bacterially infected wounds.

Synergistic Effects of Shed-Derived Exosomes, Cu2+, and an Injectable Hyaluronic Acid Hydrogel on Antibacterial, Anti-inflammatory, and Osteogenic Activity for Periodontal Bone Regeneration

The primary pathology of periodontitis involves the gradual deterioration of periodontal tissues resulting from the inflammatory reaction triggered by bacterial infection. In this study, a novel drug for periodontal pocket injection, known as the Shed-Cu-HA hydrogel, was developed by incorporating copper ions (Cu2+) and Shed-derived exosomes (Shed-exo) inside the hyaluronic acid (HA) hydrogel. Suitable concentrations of Cu2+ and Shed-exo released from Shed-Cu-HA enhanced cell viability and cell proliferation of human periodontal ligament stem cells. Additionally, the Shed-Cu-HA demonstrated remarkable antibacterial effects against the key periodontal pathogen (Aa) owing to the synergistic effect of Cu2+ and HA. Furthermore, the material effectively suppressed macrophage inflammatory response via the IL-6/JAK2/STAT3 pathway. Moreover, the Shed-Cu-HA, combining the inflammation-regulating properties of HA with the synergistic osteogenic activity of Shed-exo and Cu2+, effectively upregulated the expression of genes and proteins associated with osteogenic differentiation. The experimental findings from a mouse periodontitis model demonstrated that the administration of Shed-Cu-HA effectively reduced the extent of inflammatory cell infiltration and bacterial infections in gingival tissues and facilitated the regeneration of periodontal bone tissues and collagen after 2 and 4 weeks of injection. Consequently, it holds significant prospects for future applications in periodontitis treatment.

Coordination-Driven Self-Assembly of Metal Ion-Antisense Oligonucleotide Nanohybrids for Chronic Bacterial Infection Therapy

Bacterial infection poses a significant challenge to wound healing and skin regeneration, leading to substantial economic burdens on patients and society. Therefore, it is crucial to promptly explore and develop effective methodologies for bacterial infections. Herein, we propose a novel approach for synthesizing nanostructures based on antisense oligonucleotides (ASOs) through the coordination-driven self-assembly of Zn2+ with ASO molecules. This approach aims to provide effective synergistic therapy for chronic wound infections caused by Staphylococcus aureus (S. aureus). The resulting hybrid nanoparticles successfully preserve the structural integrity and biological functionalities of ASOs, demonstrating excellent ASO encapsulation efficiency and bioaccessibility. In vitro antibacterial experiments reveal that Zn-ASO NPs exhibit antimicrobial properties against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. This antibacterial ability is attributed to the high concentration of metal zinc ions and the generation of high levels of reactive oxygen species. Additionally, the ftsZ-ASO effectively inhibits the expression of the ftsZ gene, further enhancing the antimicrobial effect. In vivo antibacterial assays demonstrate that the Zn-ASO NPs promote optimal skin wound healing and exhibit favorable biocompatibility against S. aureus infections, resulting in a residual infected area of less than 8%. This combined antibacterial strategy, which integrates antisense gene therapy and metal-coordination-directed self-assembly, not only achieves synergistic and augmented antibacterial outcomes but also expands the horizons of ASO coordination chemistry. Moreover, it addresses the gap in the antimicrobial application of metal-coordination ASO self-assembly, thereby advancing the field of ASO-based therapeutic approaches.

Metal-polyphenol coordination nanosheets with synergistic peroxidase-like and photothermal properties for efficient antibacterial treatment

Bacterial infections pose a serious threat to human health and socioeconomics worldwide. In the post-antibiotic era, the development of novel antimicrobial agents remains a challenge. Polyphenols are natural compounds with a variety of biological activities such as intrinsic antimicrobial activity and antioxidant properties. Metal-polyphenol obtained by chelation of polyphenol ligands with metal ions not only possesses efficient antimicrobial activity but also excellent biocompatibility, which has great potential for application in biomedical and food packaging fields. Herein, we developed metal-polyphenol coordination nanosheets named copper oxidized tannic acid quinone (CuTAQ) possessing efficient antibacterial and anti-biofilm effects, which was synthesized by a facile one-pot method. The synthesis was achieved by chelation of partially oxidized tannic acid (TA) with Cu2+ under mild conditions, which supports low-cost and large-scale production. It was demonstrated that CuTAQ exhibited high antibacterial activity via disrupting the integrity of bacterial cell membranes, inducing oxidative stress, and interfering with metabolism. In addition, CuTAQ exhibits excellent peroxidase catalytic activity and photothermal conversion properties, which play a significant role in enhancing its bactericidal and biofilm scavenging abilities. This study provides insights for rational design of innovative metal-polyphenol nanomaterials with efficient antimicrobial properties.

Metal natural product complex Ru-procyanidins with quadruple enzymatic activity combat infections from drug-resistant bacteria

Bacterial infection hampers wound repair by impeding the healing process. Concurrently, inflammation at the wound site triggers the production of reactive oxygen species (ROS), causing oxidative stress and damage to proteins and cells. This can lead to chronic wounds, posing severe risks. Therefore, eliminating bacterial infection and reducing ROS levels are crucial for effective wound healing. Nanozymes, possessing enzyme-like catalytic activity, can convert endogenous substances into highly toxic substances, such as ROS, to combat bacteria and biofilms without inducing drug resistance. However, the current nanozyme model with single enzyme activity falls short of meeting the complex requirements of antimicrobial therapy. Thus, developing nanozymes with multiple enzymatic activities is essential. Herein, we engineered a novel metalloenzyme called Ru-procyanidin nanoparticles (Ru-PC NPs) with diverse enzymatic activities to aid wound healing and combat bacterial infections. Under acidic conditions, due to their glutathione (GSH) depletion and peroxidase (POD)-like activity, Ru-PC NPs combined with H2O2 exhibit excellent antibacterial effects. However, in a neutral environment, the Ru-PC NPs, with catalase (CAT) activity, decompose H2O2 to O2, alleviating hypoxia and ensuring a sufficient oxygen supply. Furthermore, Ru-PC NPs possess exceptional antioxidant capacity through their superior superoxide dismutase (SOD) enzyme activity, effectively scavenging excess ROS and reactive nitrogen species (RNS) in a neutral environment. This maintains the balance of the antioxidant system and prevents inflammation. Ru-PC NPs also promote the polarization of macrophages from M1 to M2, facilitating wound healing. More importantly, Ru-PC NPs show good biosafety with negligible toxicity. In vivo wound infection models have confirmed the efficacy of Ru-PC NPs in inhibiting bacterial infection and promoting wound healing. The focus of this work highlights the quadruple enzymatic activity of Ru-PC NPs and its potential to reduce inflammation and promote bacteria-infected wound healing.

Smart Enzyme-Like Polyphenol-Copper Spray for Enhanced Bacteria-Infected Diabetic Wound Healing

Developing functional medical materials is urgent to treat diabetic wounds with a high risk of bacterial infections, high glucose levels and oxidative stress. Here, a smart copper-based nanocomposite acidic spray has been specifically designed to address this challenge. This copper-based nanocomposite is pH-responsive and has multienzyme-like properties. It enables the spray to effectively eliminate bacteria and alleviate tissue oxidative pressure, thereby accelerating the healing of infected diabetic wounds. The spray works by generating hydroxyl radicals through catalysing H2O2, which has a high sterilization efficiency of 97.1%. As alkaline micro-vessel leakage neutralizes the acidic spray, this copper-based nanocomposite modifies its enzyme-like activity to eliminate radicals. This reduces the level of reactive oxygen species in diabetic wounds by 45.3%, leading to a similar wound-healing effect between M1 diabetic mice and non-diabetic ones by day 8. This smart nanocomposite spray provides a responsive and regulated microenvironment for treating infected diabetic wounds. It also offers a convenient and novel approach to address the challenges associated with diabetic wound healing.

Copper Nanodots-Based Hybrid Hydrogels with Multiple Enzyme Activities for Acute and Infected Wound Repair

Effectively controlling bacterial infection, reducing the inflammation and promoting vascular regeneration are all essential strategies for wound repair. Nanozyme technology has potential applications in the treatment of infections because its non-antibiotic dependent, topical and noninvasive nature. In wound management, copper-based nanozymes have emerged as viable alternatives to antibiotics. In this study, an ultrasmall cupric enzyme with high enzymatic activity is synthesized and added to a nontoxic, self-healing, injectable cationic guar gum (CG) hydrogel network. The nanozyme exhibits remarkable antioxidant properties under neutral conditions, effectively scavenging reactive nitrogen and oxygen species (RNOS). Under acidic conditions, Cu NDs have peroxide (POD) enzyme-like activity, which allows them to eliminate hydrogen peroxides and produce free radicals locally. Antibacterial experiments show that they can kill bacteria and remove biofilms. It reveals that low concentrations of Cu ND/CG decrease the expression of the inflammatory factors in cells and tissues, effectively controlling inflammatory responses. Cu ND/CG hydrogels also inhibit HIF-1α and promote VEGF expression in the wound with the ability to promote vascular regeneration. In vivo safety assessments reveal a favorable biosafety profile. Cu ND/CG hydrogels offer a promising solution for treating acute and infected wounds, highlighting the potential of innovative nanomaterials in wound healing.

Advanced nanozymes possess peroxidase-like catalytic activities in biomedical and antibacterial fields: review and progress

Infectious diseases caused by bacterial invasions have imposed a significant global health and economic burden. More worryingly, multidrug-resistant (MDR) pathogenic bacteria born under the abuse of antibiotics have further escalated the status quo. Nowadays, at the crossroads of multiple disciplines such as chemistry, nanoscience and biomedicine, nanozymes, as enzyme-mimicking nanomaterials, not only possess excellent bactericidal ability but also reduce the possibility of inducing resistance. Thus, nanozymes are promising to serve as an alternative to traditional antibiotics. Nanozymes that mimic peroxidase (POD) activity are also known as POD nanozymes. In recent years, POD nanozymes have become one of the most frequently reported and effective nanozymes due to their broad-spectrum bactericidal properties and unique sterilization mechanism. In this review, we introduce the mechanism as well as the classification of POD nanozymes. More importantly, to further improve the antibacterial efficacy of POD nanozymes, we elaborate on three aspects: (1) improving the physicochemical properties; (2) regulating the catalytic microenvironment; and (3) designing multimodel POD nanozymes. In addition, we review the nanosafety of POD nanozymes for discussing their potential toxicity. Finally, the remaining challenges of POD nanozymes and possible future directions are discussed. This work provides a systematic summary of POD nanozymes and hopefully contributes to the early clinical translation.

Modulation of the enzyme-like activity of CuAsp nanozyme by gallic acid and the selective detection of bisphenol A in infant food packaging

The activity modulation of nanozymes with multi-enzymatic activities has both opportunities and challenges in practical applications. In this study, we found firstly that gallic acid erosion had a significant inhibitory effect on the peroxidase-catalyzed colorimetric reaction process of copper aspartate nanozyme prepared based on aspartic acid and copper (CuAsp), and the laccase-like catalytic activity remained almost unchanged. A sensing strategy for bisphenol A was then developed based on the laccase-like activity of GA-CuAsp synthesized by gallic acid (GA) acid erosion of CuAsp, which may have less interference due to the peroxidase-like activity. The developed sensing strategy had good selectivity and interference resistant ability, with a detection limit of 0.75 μmol L-1. In addition, the method was successfully applied to detecting BPA in plastic bottled drinking water samples and infant food packaging.

Copper ion/gallic acid MOFs-laden adhesive pomelo peel sponge effectively treats biofilm-infected skin wounds and improves healing quality

Bacterial infection and scar formation remain primary challenges in wound healing. To address these issues, we developed a decellularized pomelo peel (DPP) functionalized with an adhesive PVA-TSPBA hydrogel and antibacterial gallic acid/copper MOFs. The hybrid wound dressing demonstrates favorable biocompatibility. It does not impede the proliferation of fibroblasts or immune cells and can stimulate fibroblast migration, endothelial angiogenesis, and M2 macrophage polarization. Additionally, the dressing can scavenge reactive oxygen species (ROS) and provide antioxidant effects. Furthermore, DPP + MOF@Gel effectively inhibits the viability of S. aureus and E. coli in vitro and in vivo. The histological observations revealed enhanced granulation tissue formation, re-epithelialization, and angiogenesis in the DPP + MOF@Gel group compared to other groups. The local immune response also shifted from a pro-inflammatory to a pro-regenerative status with DPP + MOF@Gel treatment. The skin incision stitching experiment further exhibits DPP + MOF@Gel could reduce scar formation during wound healing. Taken together, the hybrid DPP + MOF@Gel holds great promise for treating bacteria-infected skin wounds and inhibiting scar formation during wound healing.

Procedural Promotion of Multiple Stages in the Wound Healing Process by Graphene-Spiky Silica Heterostructured Nanoparticles

Background

Multiple stages including hemostasis, inflammation, proliferation, and remodeling were involved in the wound healing process. The increase in nanomaterials in recent years has extended the scope of tools for wound healing; however, it is still difficult to achieve the four multistage procedures simultaneously.

Materials and Methods

In this study, graphene-spiky silica heterostructured nanoparticles (GS) were synthesized for the procedural acceleration of the multistage in wound healing process. The nanobridge effect of GS was analyzed through the adhesion of two skins, the antibacterial effect was assessed in Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria, cell proliferation and migration were investigated in mouse embryonic fibroblast (NIH-3T3) cells, and the in vivo wound healing effect was examined in female BALB/c mice with a cutting wound and E. coli or S. aureus bacteria infection on the back.

Results

First, GS has a strong nanobridge effect on the rapid closure of wounds because the spiky architecture on the surface of GS facilitates the adhesion of skins, promoting the hemostasis stage. Second, graphene exhibits antimicrobial activities both in chemical and physical interactions, especially under simulated sunlight irradiation. Third, graphene plays an important role in scaffolding function, together with the spiky topographical architecture of GS, accelerating the proliferation and maturation stages.

Conclusion

By periodically promoting every stage of wound healing, GS combined with simulated sunlight irradiation could significantly accelerate wound healing. With a simple composition and compact structure but multiple functions, this strategy will be the guideline for the development of ideal wound-healing nanomaterials.

Bimetallic oxide Cu-Fe3O4 nanoclusters with multiple enzymatic activities for wound infection treatment and wound healing

Infections and oxidative stress complicate wound healing. In recent years, nanomaterials with natural enzymatic activities have enabled the development of new antibacterial pathways. In this study, Cu-Fe3O4 nanoclusters with multienzyme properties were synthesised. Interestingly, they exhibited activity similar to that of horseradish peroxidase (POD) in acidic environments but their functions resembled superoxide dismutase and catalase in neutral or weakly alkaline environments. In vitro studies have demonstrated the good free-radical scavenging activity of Cu-Fe3O4 nanoclusters in a neutral environment. Under acidic conditions, Cu-Fe3O4 nanoclusters combined with H2O2 demonstrated good antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). The combination of Cu-Fe3O4 and H2O2 was found to be effective in preventing MRSA infections and promoting wound healing in animal models. RNA sequencing (RNA-seq) technology revealed that chemodynamic therapy (CDT) using nanoparticles can interfere with metabolic processes such as galactose metabolism in MRSA bacteria, destroy the transport system on the surface of MRSA, and affect quorum sensing to hinder the formation of biofilms, thus achieving effective antibacterial efficacy. The use of Cu-Fe3O4 nanoclusters as a novel class of multi-catalytically active nanozymes in the anti-infection of disease-causing pathogens and wound healing has significant potential. STATEMENT OF SIGNIFICANCE: Cu-Fe3O4 nanoclusters with multienzyme properties were successfully prepared by a solvothermal method. Cu-Fe3O4 nanoclusters exhibited horseradish peroxidase (POD)-like activity in acidic environments and also showed synergistic effects similar to superoxide dismutase peroxidase in neutral or weakly basic environments. More importantly, these Cu-Fe3O4 nanoclusters showed high biosafety with no apparent in vivo toxicity. Chemodynamic therapy (CDT) using Cu-Fe3O4 nanoclusters was revealed by RNA sequencing (RNA-Seq) technology to interfere with the metabolic processes of MRSA bacteria, such as galactose metabolism, disrupt the MRSA surface transport system, and impede biofilm formation, resulting in effective antibacterial efficacy. The use of Cu-Fe3O4 nanoclusters for anti-infection and wound healing of pathogenic pathogens has significant potential as a novel class of multi-catalytic active nanoclusters.

Recent Advancements in the Formulation of Nanomaterials-Based Nanozymes, Their Catalytic Activity, and Biomedical Applications

Nanozymes are nanoparticles with intrinsic enzyme-mimicking properties that have become more prevalent because of their ability to outperform conventional enzymes by overcoming their drawbacks related to stability, cost, and storage. Nanozymes have the potential to manipulate active sites of natural enzymes, which is why they are considered promising candidates to function as enzyme mimetics. Several microscopy- and spectroscopy-based techniques have been used for the characterization of nanozymes. To date, a wide range of nanozymes, including catalase, oxidase, peroxidase, and superoxide dismutase, have been designed to effectively mimic natural enzymes. The activity of nanozymes can be controlled by regulating the structural and morphological aspects of the nanozymes. Nanozymes have multifaceted benefits, which is why they are exploited on a large scale for their application in the biomedical sector. The versatility of nanozymes aids in monitoring and treating cancer, other neurodegenerative diseases, and metabolic disorders. Due to the compelling advantages of nanozymes, significant research advancements have been made in this area. Although a wide range of nanozymes act as potent mimetics of natural enzymes, their activity and specificities are suboptimal, and there is still room for their diversification for analytical purposes. Designing diverse nanozyme systems that are sensitive to one or more substrates through specialized techniques has been the subject of an in-depth study. Hence, we believe that stimuli-responsive nanozymes may open avenues for diagnosis and treatment by fusing the catalytic activity and intrinsic nanomaterial properties of nanozyme systems.