The CuO and AgO co-modified ZnO nanocomposites for promoting wound healing in Staphylococcus aureus infection

Recent advances in nanomaterials and their mechanisms for infected wounds management

Wounds infected by bacteria pose a considerable challenge in the field of healthcare, particularly with the increasing prevalence of antibiotic-resistant pathogens. Traditional antibiotics often fail to achieve effective results due to limited penetration, resistance development, and inadequate local concentration at wound sites. These limitations necessitate the exploration of alternative strategies that can overcome the drawbacks of conventional therapies. Nanomaterials have emerged as a promising solution for tackling bacterial infections and facilitating wound healing, thanks to their distinct physicochemical characteristics and multifunctional capabilities. This review highlights the latest developments in nanomaterials that demonstrated enhanced antibacterial efficacy and improved wound healing outcomes. The antibacterial mechanisms of nanomaterials are varied, including ion release, chemodynamic therapy, photothermal/photodynamic therapy, electrostatic interactions, and delivery of antibacterial drugs, which not only combat bacterial infections but also address the challenges posed by biofilms and antibiotic resistance. Furthermore, these nanomaterials create an optimal environment for tissue regeneration, promoting faster wound closure. By leveraging the unique attributes of nanomaterials, there is a significant opportunity to revolutionize the management of infected wounds and markedly improve patient outcomes.

Engineering dual-driven pro-angiogenic nanozyme based on porous silicon for synergistic acceleration of burn infected wound healing

The high mortality risk of burn infected wounds has dictated the clinical need for the development of new biomaterials that can regulate multiple aspects of the healing process in a high-quality manner. Although nanozymes have made progress in inflammation modulation and antibacterial management, they often lack the ability in pro-angiogenesis, which greatly limits their functional application in the synergistic treatment of burn infected wounds. In this study, a smart pro-angiogenic nanozyme is simply and efficiently synthesized by in situ reduction of Pt precursors on porous silicon (PSi) nanocarriers. Owing to the hybridization of Pt, the Pt-decorated PSi (Pt@PSi) nanocomposites exhibit excellent near-infrared (NIR) photothermal activity and peroxidase-like catalytic activity, which can be used for co-efficient antibacterial treatment. After exposure to 808 nm NIR laser, Pt@PSi-based photothermal and nano-catalytic combined therapy can achieve more than 95 % bacterial inhibition in vitro. More importantly, under the stimulation of NIR laser and nanozyme, the smart Pt@PSi nanocomposites can efficiently release bioactive inorganic Si ions from the PSi skeleton, which can efficiently promote endothelial cell migration, tube formation, and angiogenesis. Furthermore, In vivo animal studies have demonstrated that Pt@PSi-based combination therapy can significantly accelerate the healing of infected burn infections by inhibiting bacterial growth, scavenging reactive oxygen species, and promoting angiogenesis with a favorable biosafety. Overall, the dual-driven pro-angiogenic nanozyme based on PSi expands the functional application of nanozyme, providing a novel combined strategy for efficient care of difficult-to-heal burn infected wounds.

Electrospun Nanofibers for the Delivery of Endolysin/Dendronized Ag-NPs Complex Against Pseudomonas aeruginosa

Purpose

As bacterial resistance to antibiotics increases, there is an urgent need to identify alternative antibacterial agents and improve antibacterial materials. One is the controlled transport of antibacterial agents that prevents infection with drug-resistant bacteria, especially in the treatment of difficult-to-heal wounds.

Methods

This work presents the use of electrospun PLCL/PVP (poly(L-lactide-co-ε-caprolactone/polyvinylpyrrolidone) nanofibers modified with two agents with antibacterial properties but with different mechanisms of action, that is, dendritic silver nanoparticles (Dend-AgNPs) and endolysin.

Results

The nanomat prepared in this manner showed significant antibacterial activity against antibiotic-resistant Pseudomonas aeruginosa strains, inhibiting their growth and production of key pigments and virulence factors. Moreover, the use of nanofibers as carriers of the selected factors significantly reduced their cytotoxicity towards human fibroblasts.

Conclusion

The results confirmed the possibility of using the presented product as an innovative dressing material, opening new perspectives for the treatment of wounds and combating bacterial infections with drug-resistant bacteria.

A multifunctional biosensor for selective identification, sensitive detection and efficient photothermal sterilization of Salmonella typhimurium and Staphylococcus aureus

BACKGROUND

The foodborne pathogens, e.g., Salmonella typhimurium (S. typ) and Staphylococcus aureus (S. aureus), pose a serious threat to human health. Accurate identification, rapid detection and efficient inactivation are crucial in the early diagnosis and treatment of S. typ and S. aureus. To date, however, the majority of studies have only concentrated on the construction of single-function biological platform for detection or inactivation of S. typ and S. aureus. Therefore, it is imperative to develop a multifunctional surface-enhanced Raman scattering (SERS) biosensor that can effectively sterilize S. typ and S. aureus while simultaneously achieving sensitive detection and selective identification.

RESULTS

Herein, we designed and constructed a multifunctional SERS biosensor based on sandwich structure of "capture probe/bacteria/signal probe" in order to simultaneously identify, detect and kill S. typ and S. aureus. Aptamer-modified ZnO/Ag was used as a capture probe to accurately identify and capture the target bacteria in complex environments. Au@Ag-4-MPBA-Aptamer was employed as signal probe to provide the corresponding bacterial SERS "fingerprint" information. The SERS enhancement mechanism of the sandwich-structure ZnO/Ag-Au@Ag SERS substrate was discussed. The sandwich-type SERS biosensor exhibited the strong localized surface plasmon resonance (LSPR) effect and the detection limit for S. typ and S. aureus was as low as 10 cfu/mL. Furthermore, the sandwich-type SERS biosensor offered excellent photothermal conversion efficiency (54.32 %), enabling photothermal killing of target bacteria when exposed to laser irradiation.

SIGNIFICANCE AND NOVELTY

A dual enhancement strategy based on a sandwich structure was proposed to maximize the sensitivity of SERS signals using synergistic action of electromagnetic enhancement and chemical enhancement. SERS enhancement factor (EF) was as high as 4.67 × 105. In addition, the sandwich-type SERS biosensor not only exhibited negligible cytotoxicity, but also was proved to be a promising tool for photothermally inactivate of S. typ and S. aureus in food samples.

Exploring nanobioceramics in wound healing as effective and economical alternatives

Wound healing is a sophisticated process for which various treatment methods have been developed. Bioceramics with the ability to release inorganic ions in biological environments play a crucial role in cellular metabolism and exhibit bactericidal activity, contributing to numerous physiological processes. Their multifaceted roles in biological systems highlight their significance. The release of different metallic ions from bioceramics enables the repair of both hard and soft tissues. These ions may be effective in cell motility, proliferation, differentiation, adhesion, angiogenesis, and antibiosis. Unlike conventional medications, the bioactivity and antibacterial properties of bioceramics are typically not associated with side effects or bacterial resistance. Bioceramics are commonly recognized for their capcity to facilitate the healing of hard tissues due to their exceptional mechanical properties. In this review, we first explore wound treatment and its prevalent methods, and subsequently, we discuss the application of three primary categories of bioceramics-oxide ceramics, silicate-based ceramics, and calcium-phosphate ceramics-in the context of wound treatment. This review introduces bioceramics as a cost-effective and efficient alternative for wound repair. Our aim is to inspire researchers to incorporate bioceramics with other biomaterials to achieve enhanced, economical, expedited, and safer wound healing.

Antibiotic Nanoparticles-Loaded Wound Dressings Against Pseudomonas aeruginosa's Skin Infection: A Systematic Review

Pseudomonas aeruginosa (P. aeruginosa) is a common nosocomial pathogen that can cause severe infections in critically ill patients. Due to its resistance to multiple drugs, it is challenging to treat, which can result in serious illness and death. Conventional treatments for infected wounds often involve the topical or systemic application of antibiotics, which can lead to systemic toxicity and the development of drug resistance. The combination of wound dressings that promote wound healing with nanoparticles (NPs) represents a revolutionary strategy for optimizing the safety and efficacy of antibiotics. This review assesses a systematic search to identify the latest approaches where the evaluation of wound dressings loaded with antibiotic NPs is conducted. The properties of NPs, the features of wound dressings, the antimicrobial activity and biocompatibility of the different strategies are analyzed. The results indicate that most research in this field is focused on dressings loaded with silver NPs (57.1%) or other inorganic materials (22.4%). Wound dressings loaded with polymeric NPs and carbon-based NPs represent 14.3% and 6.1% of the evaluated studies, respectively. Nevertheless, there are no clinical trials that have evaluated the efficacy of NPs-loaded wound dressings in patients. Further research is required to ensure the safety of these treatments and to translate the findings from the bench to the bedside.

Apt-Conjugated PDMS-ZnO/Ag-Based Multifunctional Integrated Superhydrophobic Biosensor with High SERS Activity and Photocatalytic Sterilization Performance

Sensitive detection and efficient inactivation of pathogenic bacteria are crucial for halting the spread and reproduction of foodborne pathogenic bacteria. Herein, a novel Apt-modified PDMS-ZnO/Ag multifunctional biosensor has been developed for high-sensitivity surface-enhanced Raman scattering (SERS) detection along with photocatalytic sterilization towards Salmonella typhimurium (S. typhimurium). The distribution of the electric field in PDMS-ZnO/Ag with different Ag sputtering times was analyzed using a finite-difference time-domain (FDTD) algorithm. Due to the combined effect of electromagnetic enhancement and chemical enhancement, PDMS-ZnO/Ag exhibited outstanding SERS sensitivity. The limit of detection (LOD) for 4-MBA on the optimal SERS substrate (PZA-40) could be as little as 10-9 M. After PZA-40 was modified with the aptamer, the LOD of the PZA-40-Apt biosensor for detecting S. typhimurium was only 10 cfu/mL. Additionally, the PZA-40-Apt biosensor could effectively inactivate S. typhimurium under visible light irradiation within 10 min, with a bacterial lethality rate (Lb) of up to 97%. In particular, the PZA-40-Apt biosensor could identify S. typhimurium in food samples in addition to having minimal cytotoxicity and powerful biocompatibility. This work provides a multifunctional nanoplatform with broad prospects for selective SERS detection and photocatalytic sterilization of pathogenic bacteria.

Multifunctional Microneedle Patch Based on Metal-Phenolic Network with Photothermal Antimicrobial, ROS Scavenging, Immunomodulatory, and Angiogenesis for Programmed Treatment of Diabetic Wound Healing

In diabetic patients with skin injuries, bacterial proliferation, accumulation of reactive oxygen species (ROS) in the tissues, and impaired angiogenesis make wound healing difficult. Therefore, eliminating bacteria, removing ROS, and promoting angiogenesis are necessary for treating acute diabetic wounds. In this study, benefiting from the ability of polyphenols to form a metal-phenolic network (MPN) with metal ions, TA-Eu MPN nanoparticles (TM NPs) were synthesized. The prepared photothermal agent CuS NPs and TM NPs were then loaded onto the supporting base and needle tips of PVA/HA (PH) microneedles, respectively, to obtain PH/CuS/TM microneedles. Antibacterial experiments showed that microneedles loaded with CuS NPs could remove bacteria by the photothermal effect. In vitro experiments showed that the microneedles could effectively scavenge ROS, inhibit macrophage polarization to the M1 type, and induce polarization to the M2 type as well as have the ability to promote vascular endothelial cell migration and angiogenesis. Furthermore, in vivo experiments showed that PH/CuS/TM microneedles accelerated wound healing by inhibiting pro-inflammatory cytokines and promoting angiogenesis in a diabetic rat wound model. Therefore, PH/CuS/TM microneedles have efficient antibacterial, ROS scavenging, anti-inflammatory, immunomodulatory, and angiogenic abilities and hold promise as wound dressings for treating acute diabetic wounds.

NIR light-activated nanocomposites combat biofilm formation and enhance antibacterial efficacy for improved wound healing

Nanoparticle-based therapies are emerging as a pivotal frontier in biomedical research, showing their potential in combating infections and facilitating wound recovery. Herein, selenium-tellurium dopped copper oxide nanoparticles (SeTe-CuO NPs) with dual photodynamic and photothermal properties were synthesized, presenting an efficient strategy for combating bacterial infections. In vitro evaluations revealed robust antibacterial activity of SeTe-CuO NPs, achieving up to 99% eradication of bacteria and significant biofilm inhibition upon near-infrared (NIR) irradiation. Moreover, in vivo studies demonstrated accelerated wound closure upon treatment with NIR-activated SeTe-CuO NPs, demonstrating their efficacy in promoting wound healing. Furthermore, SeTe-CuO NPs exhibited rapid bacterial clearance within wounds, offering a promising solution for wound care. Overall, this versatile platform holds great promise for combating multidrug-resistant bacteria and advancing therapeutic interventions in wound management.

In situ forming Hydrogel with adding ZnO Nano-particle for effectively methicillin-resistant Staphylococcus aureus infected frostbite injury

Hydrogel has emerged as a promising wound dressing material, and in situ forming hydrogel has emerged as a promising wound dressing recently. But most in situ forming hydrogel are normally unstable. Herein, we report an in-situ forming hydrogel synthesized from poly(Nisopropylacrylamide166-co-n-butyl acrylate9)-poly(ethyleneglycol)-poly(N-isopropylacrylamide166-co-n-butyl acrylate9) copolymer (P(NIPAM166-co-nBA9)-PEG-P(NIPAM166-conBA9), denoted as PEP) and zinc oxide nano-particle(ZnO nano-particle) in response to skin temperature. This thermoresponsive hydrogel exhibits sol-gel reversibility at high temperatures, which is closed to the temperature of human skin. To investigate its healing effects, we used the Hydrogel dressing® in an SD rat model. The biocompatibility and antibacterial ability against methicillin-resistant Staphylococcus aureus(MRSA) of this PEP-ZnO hydrogel wound dressing are confirmed in vitro and in vivo, which could transparently promote the healing of a MRSA-infected frostbitten skin Injury.

Materials and methods

Thirty rats were randomly divided into two groups. The treatment group received hydrogel and transparent film dressing 30 min to 1 h post-burn, while the control group received only cotton dressing. The wound area was measured, and the wound closure rate was calculated on days 3, 7, and 14 post-surgery. Tissue samples were collected from each rat on these days and stored at -80 °C for histological analysis using H&E, Masson and immunohistochemical staining. This analysis assessed factors such as granulation tissue length, re-epithelialization, re-angiogenesis, collagen deposition, inflammatory cell infiltration, and collagen production. Clinical and histological assessments at 14 days showed more rapid healing in the hydrogel dressing group compared to the control group.

Conclusion

Our results indicate that the design of our hydrogel for cooling injury wounds effectively improves healing and mitigates the damage from low temperatures.

An antibacterial membrane based on Janus bacterial cellulose with nano-sized copper oxide through polydopamine conjugation for infectious wound healing

Bacterial cellulose (BC) produced by Acetobacter xylinum has great advantages in wound dressing. However, the structural limitation under static culture, and lack of antibacterial properties restrict its application, especially for infectious wound healing. The present study reported an original wound dressing, which was composed of a Janus BC membrane with antibacterial nano-sized copper oxide (CuO) through polydopamine (PDA) conjugation to promote wound healing under infectious condition. The finished product (CuO/PDA/BC membrane) exhibited favorable air permeability, high hydrophilicity and good mechanical properties, as well as strong antibacterial effects by the sustained release of CuO and photothermal effect of CuO/PDA. Furthermore, CuO/PDA/BC membrane inhibited inflammatory response and promoted wound healing in an infectious wound model in vivo. These results suggested that our CuO/PDA/BC membrane had great potential as wound dressing for infectious wound healing.

In Situ Formation of Hydrogel Wound Dressing Based on Carboxymethyl Chitin/Tannic Acid for Promoting Skin Wound Healing

Triggering the healing process of drug-resistant bacteria-infected wounds has attracted great attention due to global morbidity that may induce gangrene, amputation, and even death. Here, a chitin derivative, carboxymethyl chitosan (CMC), tannic acid (TA), and Cu2+ were used for hydrogel engineering. Using sodium bicarbonate as the neutralizer and reductant, hydrogen bonds between CMC and TA and in situ Cu(OH)2 generation via ion coordination force between Cu2+ and TA facilitated the synthesis of CMC/TA/Cu hydrogel. Cu2+ and TA release, cytotoxicity, in vitro cell migration, angiogenesis, and antidrug-resistant bacteria were measured. Besides, wound closure was evaluated in vivo using the methicillin-resistant Staphylococcus aureus (MRSA)-infected excisional dermal wound mouse model. Negligible toxicity was observed both in vitro and in vivo. Dermal cell migration and angiogenesis were significantly enhanced. In vivo, the CMC/TA/Cu hydrogel induced effective re-epithelialization, collagen deposition, inflammatory alleviation, and MRSA inhibition during wound repair in mice. All these results confirmed that the CMC/TA/Cu hydrogel is a promising novel dressing for chronic wound healing in clinic.

Harmless and resourceful utilization of solid waste: Multi physical field regulation in the microbiological treatment process of solid waste treatment

Solid waste (SW) treatment methods mainly include physical, chemical, and biological methods, while physical and chemical methods have advantages such as fast effectiveness and short treatment time, but have high costs and were prone to secondary pollution. Due to the advantages of mild conditions and environmental protection, microbial methods have attracted the attention of numerous researchers. Recently, promotion of biological metabolic activity in biotreatment technology by applying multiple physical conditions, and reducing the biochemical reaction energy base to promote the transfer of protons and electrons, has made significant progress in harmless and resourceful utilization of SW. This paper main summarized the harmless and resourceful treatment methods of common bulk SW. The research of physical field-enhanced microbial treatment of inorganic solid waste (ISW) and organic solid waste (OSW) was discussed. The advantages and mechanisms of microbial treatment compared to traditional SW treatment methods were analyzed. The multi-physical field coupling enhanced microbial treatment technology was proposed to further improving the efficiency of large-scale treatment of bulk SW. The application prospects and potential opportunities of this technology were analyzed. Novel research ideas for the large-scale harmless and resourceful treatment of bulk SW were provided.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

ZnO-Doped Metal-Organic Frameworks Nanoparticles: Antibacterial Activity and Mechanisms

Metal-Organic Frameworks (MOFs) offer new ideas for the design of antibacterial materials because of their antibacterial properties, high porosity and specific surface area, low toxicity and good biocompatibility compared with other nanomaterials. Herein, a novel antimicrobial nanomaterial, MIL-101(Fe)@ZnO, has been synthesized by hydrothermal synthesis and characterized by FTIR, UV-vis, ICP-OES, XRD, SEM, EDS and BET to show that the zinc ions are doped into the crystal lattice of MIL-101(Fe) to form a Fe-Zn bimetallic structure. MIL-101(Fe)@ZnO was found to be effective against a wide range of antibacterial materials including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Acinetobacter junii and Staphylococcus epidermidis. It has a significant antibacterial effect, weak cytotoxicity, high safety performance and good biocompatibility. Meanwhile, MIL-101(Fe)@ZnO was able to achieve antibacterial effects by causing cells to produce ROS, disrupting the cell membrane structure, and causing protein leakage and lipid preoxidation mechanisms. In conclusion, MIL-101(Fe)@ZnO is an easy-to-prepare antimicrobial nanomaterial with broad-spectrum bactericidal activity and low toxicity.

Recent Advances in Copper-Based Materials for Sustainable Environmental Applications

In recent years, copper-based nanomaterials have gained significant attention for their practical applications due to their cost-effectiveness, thermal stability, selectivity, high activity, and wide availability. This review focuses on the synthesis and extensive applications of copper nanomaterials in environmental catalysis, addressing knowledge gaps in pollution management. It highlights recent advancements in using copper-based nanomaterials for the remediation of heavy metals, organic pollutants, pharmaceuticals, and other contaminants. Also, it will be helpful to young researchers in improving the suitability of implementing copper-based nanomaterials correctly to establish and achieve sustainable goals for environmental remediation.