Antibacterial Strategies Research Articles

Electron Reservoir MoO3–x‐Driven Cu+ Doped Nanozyme with Enhanced Antibacterial Activity via Disrupting Redox Homeostasis

Comprehensive SummaryRedox nanozymes offer an appealing reactive oxygen species (ROS)‐based antibacterial strategy via disrupting intracellular homeostasis, however, they still face many obstacles such as low enzymic activity and irreversible loss of catalytic active center. Meanwhile, the antioxidant glutathione (GSH) overexpressed in infected sites would limit the therapy efficiency. Herein, we develop a multifunctional nanozyme based on copper(I) (Cu+) ion doped MoO3–x (Cu+‐MoO3–x) by a simple yet efficient oxygen vacancy‐reduced strategy without any pretreatment or additional agents. The resultant Cu+‐MoO3–x hybrid possesses enhanced peroxidase‐like (POD‐like) activity, rapid GSH‐depleting function and biodegradable ability. It can achieve highly efficient elimination of Pseudomonas aeruginosa (P. aeruginosa) via disrupting cellular redox balance. More intriguingly, GSH‐depleting redox reaction between Cu+‐MoO3–x and GSH could translate Mo6+ into Mo5+, thereby leading to partial recovery of POD‐like activity of Cu+‐MoO3–x hybrid for continuous ∙OH generation. In vitro and in vivo experiments demonstrated that Cu+‐MoO3–x hybrid had stronger antibacterial property compared to MoO3–x by rapid GSH consumption and plentiful ∙OH generation without providing extra H2O2, as well as neglective toxicity to healthy organs. In view of its remarkable enzymic activity and good biosafety, the developed Cu+‐MoO3–x redox nanozyme can be used as a promising antimicrobial for P. aeruginosa infection.

AMPActiPred: A three‐stage framework for predicting antibacterial peptides and activity levels with deep forest

AbstractThe emergence and spread of antibiotic‐resistant bacteria pose a significant public health threat, necessitating the exploration of alternative antibacterial strategies. Antibacterial peptide (ABP) is a kind of antimicrobial peptide (AMP) that has the potential ability to fight against bacteria infection, offering a promising avenue for developing novel therapeutic interventions. This study introduces AMPActiPred, a three‐stage computational framework designed to identify ABPs, characterize their activity against diverse bacterial species, and predict their activity levels. AMPActiPred employed multiple effective peptide descriptors to effectively capture the compositional features and physicochemical properties of peptides. AMPActiPred utilized deep forest architecture, a cascading architecture similar to deep neural networks, capable of effectively processing and exploring original features to enhance predictive performance. In the first stage, AMPActiPred focuses on ABP identification, achieving an Accuracy of 87.6% and an MCC of 0.742 on an elaborate dataset, demonstrating state‐of‐the‐art performance. In the second stage, AMPActiPred achieved an average GMean at 82.8% in identifying ABPs targeting 10 bacterial species, indicating AMPActiPred can achieve balanced predictions regarding the functional activity of ABP across this set of species. In the third stage, AMPActiPred demonstrates robust predictive capabilities for ABP activity levels with an average PCC of 0.722. Furthermore, AMPActiPred exhibits excellent interpretability, elucidating crucial features associated with antibacterial activity. AMPActiPred is the first computational framework capable of predicting targets and activity levels of ABPs. Finally, to facilitate the utilization of AMPActiPred, we have established a user‐friendly web interface deployed at https://awi.cuhk.edu.cn/∼AMPActiPred/.

T6SS nuclease effectors in Pseudomonas syringae act as potent antimicrobials in interbacterial competition.

The phytopathogen Pseudomonas syringae employs an active type VI secretion system (T6SS) to outcompete other microorganisms in the natural environment, particularly during the epiphytic growth in the phyllosphere. By examining two T6SS clusters in P. syringae MB03, T6SS-1 is found to be effective in killing Escherichia coli cells. We highlight the excellent antibacterial effect of two T6SS DNase effectors, namely, Tde1 and Tde4. Both of them function as nuclease effectors, leading to DNA degradation and cell filamentation in prey cells, ultimately resulting in cell death. Our findings deepen our understanding of the T6SS effector repertoires used in P. syringae and will facilitate the development of effective antibacterial strategies.

Synergistic antibacterial effects of closantel and its enantiomers in combination with colistin against multidrug resistant gram-negative bacteria.

Drug combinations and repurposing have recently provided promising alternatives to cope with the increasingly severe issue of antibiotic resistance and depletion of natural drug molecular repertoires that undermine traditional antibacterial strategies. Closantel, an effective adjuvant, reverses antibiotic resistance in gram-negative bacteria. Herein, the combined antibacterial enantioselectivity of closantel is presented through separate enantiomer studies. Despite yielding unexpected differences, two closantel enantiomers (R, S) increased colistin activity against gram-negative bacteria both in vitro and in vivo. The fractional inhibitory concentration indices of R-closantel and S-closantel combined with colistin against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli ranged from 0.0087 to 0.5004 and from 0.0117 to 0.5312, respectively. This difference was further demonstrated using growth inhibition assays and time-killing curves. Mechanistically, a higher intracellular concentration of R-CLO is more effective in enhancing the antimicrobial activity of combination. A mouse cutaneous infection model confirmed the synergistic stereoselectivity of closantel. This discovery provides novel insights for developing precision medication and containment of increasing antibiotic resistance.

Bacteriophage therapy in musculoskeletal infections: from basic science to clinical application.

The treatment of musculoskeletal infections (MSIs), including periprosthetic joint infection (PJI) and fracture-related infection (FRI), is often complicated by biofilm-related challenges necessitating multiple revision surgeries and incurring substantial costs. The emergence of antimicrobial resistance (AMR) adds to the complexity of the problem, leading to increased morbidity and healthcare expenses. There is an urgent need for novel antibacterial strategies, with the World Health Organization endorsing non-traditional approaches like bacteriophage (phage) therapy. Phage therapy, involving the targeted application of lytic potent phages, shows promise in the treatment of MSIs. Although historical clinical trials and recent case studies present significant milestones in the evolution of phage therapy over the past century, challenges persist, including variability in study designs, administration protocols and phage selection. Efforts to enhance treatment efficacy consist of personalized phage therapy and combination with antibiotics. Future perspectives entail addressing regulatory barriers, standardizing treatment protocols, and conducting high-quality clinical trials to establish phage therapy's efficacy for the treatment of MSIs. Initiatives like the PHAGEFORCE study and the PHAGEinLYON Clinic programme aim to streamline phage therapy, facilitating personalized treatment approaches and systematic data collection to advance its clinical utility in these challenging infections.

Antimicrobial properties of bimetallic-containing mesoporous bioglass against Enterococcus faecalis

Background/purpose:Various pulp-covering materials offer advantages in regenerative root canal treatment, but each has limitations, highlighting the need for more effective antibacterial strategies for pulp repair and regeneration. Mesoporous bioactive glasses (MBG) show significant biological activity, making them valuable in tissue/dental repair. Silver-incorporated MBG exhibits promising antibacterial effects against various bacteria; copper ions are crucial in regulating angiogenesis signals. Co-loading copper and silver in bioactive glasses has been explored to address clinical challenges. This study modified the preparation of silver-copper bimetallic mesoporous bioactive glass, analyzing their textural properties and antibacterial activity against Enterococcus faecalis. Materials and methodsThe silver-copper co-loaded bioactive glass (designated as AgCu/80S) was synthesized using a sol–gel technique with modifications. Textural analyses were carried out via X-ray diffraction, UV–Vis spectroscopy, Brunauer–Emmett–Teller analysis, and transmission electron microscope. The ion-releasing activity determined using inductively coupled plasma-mass spectrometry, and the antibacterial activity against E. faecalis was assessed through disk diffusion and kinetic bacterial growth curve. ResultsThe modification led to weaker crystallization of calcium silicate, altering ion-releasing and antibacterial activities. Ag3Cu2/80S exhibited the highest released silver ion concentration at 112.6 ppm, with an inhibition zone of 9.09 ± 0.09 mm in disk diffusion assays. However, the inhibition zone of Ag2Cu3/80S was 9.92 ± 0.04 mm, implying that the antibacterial activity may not only be influenced by silver ions. ConclusionThe AgCu/80S showed a potential antibacterial activity against E. faecalis, whereas further research on AgCu/80S glasses is necessary to optimize ion release conditions, assess bioactivities, and explore potential dental applications.

Navigating Antibacterial Frontiers: A Panoramic Exploration of Antibacterial Landscapes, Resistance Mechanisms, and Emerging Therapeutic Strategies.

The development of effective antibacterial solutions has become paramount in maintaining global health in this era of increasing bacterial threats and rampant antibiotic resistance. Traditional antibiotics have played a significant role in combating bacterial infections throughout history. However, the emergence of novel resistant strains necessitates constant innovation in antibacterial research. We have analyzed the data on antibacterials from the CAS Content Collection, the largest human-curated collection of published scientific knowledge, which has proven valuable for quantitative analysis of global scientific knowledge. Our analysis focuses on mining the CAS Content Collection data for recent publications (since 2012). This article aims to explore the intricate landscape of antibacterial research while reviewing the advancement from traditional antibiotics to novel and emerging antibacterial strategies. By delving into the resistance mechanisms, this paper highlights the need to find alternate strategies to address the growing concern.

Research on the performance and mechanism of enhancing TiO2 antibacterial and photodriven sterilization by pyrite composition

Driven by market demand and resourcefulness of low-value minerals, the preparation of low-cost visible photocatalytic bactericidal materials has become a research hotspot. Here, a simple solvothermal method was constructed FeS2 photosensitized TiO2, which is a promising antibacterial and photocatalytic sterilization strategy. The disinfection efficiency of TiO2/FeS2 for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was 95.7 and 92.4%, respectively. In the darkness, TiO2/FeS2 could wrap around the surface of bacterial cells and significantly decrease their metabolic activity of bacterial cells of E. coli and S. aureus to 21.4% and 30.1%, respectively. Under the light irradiation, TiO2/FeS2 exhibited the light absorption feature of both TiO2 and FeS2. Meanwhile, an internal electric field from FeS2 to TiO2 was established to realize electron transmission, which as dominant role cooperating with the surface redox reaction, allowed TiO2/FeS2 produced obviously higher •OH, •O2–, and 1O2 to perform an ideal disinfection effect.

Photoactive cationic conjugated microporous polymers containing pyrimidine with an ‘adsorption-kill’ antibacterial strategy for infected wound healing

Pathogenic bacterial invasion leads to severe inflammation that hinders wound healing, and it has become a major medical threat worldwide. Photodynamic therapy (PDT) has emerged as a promising strategy for treating microbial infection; however, developing a dressing with PDT effect and excellent biological functions poses a formidable challenge. Herein, a novel cationic pyrimidine-modified conjugated microporous polymer, BPyMe-CMP, was rationally designed and synthesized via a Sonogashira-Hagiwara and SN2 substitution reaction. The BPyMe-CMP exhibited weak interfacial charge transfer resistance and demonstrated superior photoinducible carrier separation, thereby displaying an excellent photoelectric response. Consequently, the BPyMe-CMP could readily generate reactive oxygen species under visible light irradiation to kill bacteria. In addition to enhancing the photogenerated electron transfer process, BPyMe-CMP also provided abundant attraction sites for bacteria to reinforce the antibacterial ability. The deposition of BPyMe-CMP onto polyvinyl alcohol-modified silk fibroin (SF/PVA) film served as a wound dressing to promote healing. The in vitro and in vivo experiments revealed that the SF/PVA@BPyMe-CMP induced M2-type macrophage polarization, promoted L929 fibroblast migration, exhibited bactericidal activity, and induced angiogenesis, which synergistically accelerated the healing of methicillin-resistant Staphylococcus aureus-infected wounds. This study provides data support to advance the construction of a multi-functional wound dressing based on pyrimidination and cationization for the treatment and rapid healing of infected wounds.

In Silico Analysis of the Ga3+/Fe3+ Competition for Binding the Iron-Scavenging Siderophores of P. aeruginosa-Implementation of Three Gallium-Based Complexes in the "Trojan Horse" Antibacterial Strategy.

The emergence of multidrug-resistant (MDR) microorganisms combined with the ever-draining antibiotic pipeline poses a disturbing and immensely growing public health challenge that requires a multidisciplinary approach and the application of novel therapies aimed at unconventional targets and/or applying innovative drug formulations. Hence, bacterial iron acquisition systems and bacterial Fe2+/3+-containing enzymes have been identified as a plausible target of great potential. The intriguing "Trojan horse" approach deprives microorganisms from the essential iron. Recently, gallium's potential in medicine as an iron mimicry species has attracted vast attention. Different Ga3+ formulations exhibit diverse effects upon entering the cell and thus supposedly have multiple targets. The aim of the current study is to specifically distinguish characteristics of great significance in regard to the initial gallium-based complex, allowing the alien cation to effectively compete with the native ferric ion for binding the siderophores pyochelin and pyoverdine secreted by the bacterium P. aeruginosa. Therefore, three gallium-based formulations were taken into consideration: the first-generation gallium nitrate, Ga(NO3)3, metabolized to Ga3+-hydrated forms, the second-generation gallium maltolate (tris(3-hydroxy-2-methyl-4-pyronato)gallium), and the experimentally proven Ga carrier in the bloodstream-the protein transferrin. We employed a reliable in silico approach based on DFT computations in order to understand the underlying biochemical processes that govern the Ga3+/Fe3+ rivalry for binding the two bacterial siderophores.

Alkylated EDTA potentiates antibacterial photodynamic activity of protoporphyrin

Antibiotic resistance has garnered significant attention due to the scarcity of new antibiotics in development. Protoporphyrin IX (PpIX)-mediated photodynamic therapy shows promise as a novel antibacterial strategy, serving as an alternative to antibiotics. However, the poor solubility of PpIX and its tendency to aggregate greatly hinder its photodynamic efficacy. In this study, we demonstrate that alkylated EDTA derivatives (aEDTA), particularly C14-EDTA, can enhance the solubility of PpIX by facilitating its dispersion in aqueous solutions. The combination of C14-EDTA and PpIX exhibits potent antibacterial activity against Staphylococcus aureus (S. aureus) when exposed to LED light irradiation. Furthermore, this combination effectively eradicates S. aureus biofilms, which are known to be strongly resistant to antibiotics, and demonstrates high therapeutic efficacy in an animal model of infected ulcers. Mechanistic studies reveal that C14-EDTA can disrupt PpIX crystallization, increase bacterial membrane permeability and sequester divalent cations, thereby improving the accumulation of PpIX in bacteria. This, in turn, enhances reactive oxygen species (ROS) production and the antibacterial photodynamic activity. Overall, this effective strategy holds great promise in combating antibiotic-resistant strains.Graphical

Structural and Biochemical Characterization of a New Phage-Encoded Muramidase, KTN6 Gp46.

Endolysins are phage-encoded lytic enzymes that degrade bacterial peptidoglycan at the end of phage lytic cycles to release new phage particles. These enzymes are being explored as an alternative to small-molecule antibiotics. The crystal structure of KTN6 Gp46 was determined and compared with a ColabFold model. Cleavage specificity was examined using a peptidoglycan digest and reversed-phase high-performance liquid chromatography coupled to mass spectrometry (HPLC/MS). The structure of KTN6 Gp46 could be determined at 1.4 Å resolution, and key differences in loops of the putative peptidoglycan binding domain were identified in comparison with its closest known homologue, the endolysin of phage SPN1S. Reversed-phase HPLC/MS analysis of the reaction products following peptidoglycan digestion confirmed the muramidase activity of Gp46, consistent with structural predictions. These insights into the structure and function of endolysins further expand the toolbox for endolysin engineering and explore their potential in enzyme-based antibacterial design strategies.

Recent progress in graphitic carbon nitride-based materials for antibacterial applications: synthesis, mechanistic insights, and utilization

Recent breakthroughs in graphitic carbon nitride (g-C3N4)-based materials have catalyzed the development of highly effective antibacterial strategies. This comprehensive review delves into the synthesis, mechanistic insights, and applications of g-C3N4 in the realm of antibacterial research. The introduction first highlights the importance of antibacterial materials, emphasizing the urgent need for innovative solutions in the face of bacterial infections and the escalating challenges posed by antibiotic resistance. Continuing, the structural attributes and distinctive characteristics of g-C3N4 are examined in detail, elucidating its inherent properties that make it a compelling candidate for antibacterial applications. Subsequently, we meticulously dissect various methods used in the synthesis of g-C3N4, encompassing both top-down and bottom-up approaches, offering valuable insights into the production of this promising nanomaterial. Furthermore, it delves deeper into the sterilization mechanisms of g-C3N4-based nanomaterials, encompassing a spectrum of strategies, including physical structure sterilization, photocatalytic antibacterial effects, enzymatic antibacterial processes, and the synergetic benefits that emerge from the fusion of these mechanisms. Then, it comprehensively examines the practical applications of g-C3N4-based nanomaterials in antibacterial endeavors, encompassing their pivotal roles in water purification, air purification, treatment of bacterial infections, and the development of antibacterial layers in diverse settings. In conclusion, we encapsulate the crux of our findings and provide a forward-looking perspective on the potential challenges and opportunities in the arena of g-C3N4-based materials for antibacterial applications. This review aspires to galvanize further exploration and innovation in the design of high-performance g-C3N4-based materials, thereby contributing to the progression of antibacterial solutions.

Deinococcus wulumuqiensis R12 synthesized silver nanoparticles with peroxidase-like activity for synergistic antibacterial application.

The use of a combination of several antibacterial agents for therapy holds great promise in reducing the dosage and side effects of these agents, improving their efficiency, and inducing potential synergistic therapeutic effects. Herein, this study provides an innovative antibacterial treatment strategy by synergistically combining R12-AgNPs with H2O2 therapy. R12-AgNPs were simply produced with the supernatant of an ionizing radiation-tolerant bacterium Deinococcus wulumuqiensis R12 by one-step under room temperature. In comparison with chemically synthesized AgNPs, the biosynthesized AgNPs presented fascinating antibacterial activity and peroxidase-like properties, which endowed it with the capability to catalyze the decomposition of H2O2 to generate hydroxyl radical. After the combination of R12-AgNPs and H2O2, an excellent synergistic bacteriostatic activity was observed for both Escherichia coli and Staphylococcus aureus, especially at low concentrations. In addition, in vitro cytotoxicity tests showed R12-AgNPs had good biocompatibility. Thus, this work presents a novel antibacterial agent that exhibits favorable synergistic antibacterial activity and low toxicity, without the use of antibiotics or a complicated synthesis process.

Стратегия эффективного административного контроля антимикробной терапии в отделении реанимации и интенсивной терапии хирургического профиля: ретроспективное пилотное исследование.

Objective: To evaluate a strategy for effective administrative control of targeted antimicrobial therapy in surgical intensive care unit (ICU) patients. Materials and methods. The study included 3522 patients who were treated in ICU No. 1 in the period 2022 to 2023. The first group (control), treatment period 2022, included 1764 patients. The second group (research), treatment period 2023, included 1758 patients. In both groups, the use of antimicrobial drugs (AMP) was carried out in accordance with the antibacterial therapy control strategy (ASCT); in group 2, systemic administrative control was additionally carried out in the form of the use of the “Effective Hospital” program and a developed analytical system with monitoring the financial stability of the unit, aimed at daily monitoring of operating activities. A comparative analysis of the frequency of use of various classes of antimicrobial agents, the incidence of infectious complications, mortality rates and financial costs between groups was performed. Results. There was a significant decrease in the consumption of AMPs of the carbapenem group from 8194 vials in 2022 to 6577 vials in 2023, which was a decrease of 19.7%; a decrease in the consumption of tetracycline group AMPs in 2023 compared to 2022, from 2338 bottles to 1581 bottles, which amounted to 32.4%; reduction in the consumption of vancomycin and linezolid in 2023 compared to 2022 from 562 vials to 313 vials, which amounted to 44.3%. There was a decrease in the incidence of VAP from 59.3 (57.6; 62.9) in 2022 to 48.1 (38.65; 61.9) units in 2023, which amounted to 10.8% (p = 0.053). The increase in the frequency of deaths from 10.9% (9.1; 12.4) in 2022 to 11.5% (10.5; 12.7) in 2023 did not have significant differences (p = 0.67). The total expenditure on AMP in 2023 significantly decreased by 22.3%, which allowed saving 1,477,205.53 rubles (p = 0.012). Conclusion. The use of a daily strategy of administrative control of operational activities and the use of antimicrobial therapy in the ICU can reduce the costs of expensive antimicrobial agents, reduce the incidence of nosocomial infectious and inflammatory complications without changing overall mortality.

Nanoarchitectonics of Bimetallic Cu-/Co-Doped Nitrogen-Carbon Nanozyme-Functionalized Hydrogel with NIR-Responsive Phototherapy for Synergistic Mitigation of Drug-Resistant Bacterial Infections.

Superbug infections and transmission have become major challenges in the contemporary medical field. The development of novel antibacterial strategies to efficiently treat bacterial infections and conquer the problem of antimicrobial resistance (AMR) is extremely important. In this paper, a bimetallic CuCo-doped nitrogen-carbon nanozyme-functionalized hydrogel (CuCo/NC-HG) has been successfully constructed. It exhibits photoresponsive-enhanced enzymatic effects under near-infrared (NIR) irradiation (808 nm) with strong peroxidase (POD)-like and oxidase (OXD)-like activities. Upon NIR irradiation, CuCo/NC-HG possesses photodynamic activity for producing singlet oxygen(1O2), and it also has a high photothermal conversion effect, which not only facilitates the elimination of bacteria but also improves the efficiency of reactive oxygen species (ROS) production and accelerates the consumption of GSH. CuCo/NC-HG shows a lower hemolytic rate and better cytocompatibility than CuCo/NC and possesses a positive charge and macroporous skeleton for restricting negatively charged bacteria in the range of ROS destruction, strengthening the antibacterial efficiency. Comparatively, CuCo/NC and CuCo/NC-HG have stronger bactericidal ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AmprE. coli) through destroying the cell membranes with a negligible occurrence of AMR. More importantly, CuCo/NC-HG plus NIR irradiation can exhibit satisfactory bactericidal performance in the absence of H2O2, avoiding the toxicity from high-concentration H2O2. In vivo evaluation has been conducted using a mouse wound infection model and histological analyses, and the results show that CuCo/NC-HG upon NIR irradiation can efficiently suppress bacterial infections and promote wound healing, without causing inflammation and tissue adhesions.

Combating infections from drug-resistant bacteria: Unleashing synergistic broad-spectrum antibacterial power with high-entropy MXene/CDs

The growing resistance of bacteria to antibiotics has posed challenges in treating associated bacterial infections, while the development of multi-model antibacterial strategies could efficient sterilization to prevent drug resistance. High-entropy MXene has emerged as a promising candidate for antibacterial synergy with inherent photothermal and photodynamic properties. Herein, a high-entropy nanomaterial of MXene/CDs was synthesized to amplify oxidative stress under near-infrared laser irradiation. Well-exfoliated MXene nanosheets have proven to show an excellent photothermal effect for sterilization. The incorporation of CDs could provide photo-generated electrons for MXene nanosheets to generate ROS, meanwhile reducing the recombination of electron-hole pairs to further accelerate the generation of photo-generated electrons. The MXene/CDs material demonstrates outstanding synergistic photothermal and photodynamic effects, possesses excellent biocompatibility and successfully eliminates drug-resistant bacteria as well as inhibits biofilm formation. While attaining a remarkable killing efficiency of up to 99.99% against drug-resistant Escherichia coli and Staphylococcus aureus, it also demonstrates outstanding antibacterial effects against four additional bacterial strains. This work not only establishes a synthesis precedent for preparing high-entropy MXene materials with CDs but also provides a potential approach for addressing the issue of drug-resistant bacterial infections.

An NIR-II-enhanced nanozyme to promote wound healing in methicillin-resistant Staphylococcus aureus infections

Deep tissue bacterial infections, especially methicillin-resistant Staphylococcus aureus (MRSA) infections, pose challenges to clinical therapy due to their low debridement efficiency and relapsing. Molybdenum disulfide (MoS2) is used in the antibacterial field as a classic photothermal agent (NIR-I) with good biocompatibility. However, due to its limited NIR-I tissue penetration ability and single treatment mode, MoS2 has poor therapeutic effects on deep tissue infection. Herein, we prepared a defect-type hybrid 2H-MoS2 nanozyme (MoWS2) using hydrothermal method fabricate the MoWS2 composite, which is a new antibacterial strategy involving photothermal and enzyme catalysis, and further enhances the activity of the nanozyme through overheating. The regulation of 2H-MoS2 defects through tungsten ion doping endows MoWS2 with better near-infrared two-region absorption (NIR-II) and enzyme catalytic performance. Antibacterial activity experiments in vitro have shown that MoWS2 can achieve efficient bactericidal activity and biofilm clearance through hyperthermia and reactive oxygen species (ROS). Deep MRSA infection experiments have shown that MoWS2 rapidly removes bacteria from subcutaneous infected tissues through photothermal therapy (PTT) and chemodynamic therapy (CDT), accelerates the dissipation of abscesses, and promotes the healing of infected wounds. Additionally, the versatile treatment mode of MoWS2 was further confirmed through tissue sectioning and immunofluorescence staining analysis. Overall, these results provide a feasible approach for achieving efficient treatment of deep tissue infections through tungsten ion doping to regulate defective 2H-MoS2. Statement of significanceThe photothermal effect of MoS2 nanosheets in the NIR-I (650-900 nm) window in anti-MRSA therapy is considered to be highly reliable and efficient in PTA. However, most of the developed PPT therapies or antimicrobial systems based on PTT therapies developed with 1T-MoS2 have in vivo sterilization temperatures of more than 55°C, which have the risk of damaging the normal tissues of the skin. In this study, we prepared W@MoS2 with a good photothermal effect (36.9%) in the NIR-II window and good peroxidase-like activity. The combined effect of PTT and CDT has a stronger bactericidal effect while avoiding high-temperature damage, which makes the W@MoS2 material more advantageous in terms of antimicrobial effect.

Platinum Nanoparticles Regulated V2C MXene Nanoplatforms with NIR-II Enhanced Nanozyme Effect for Photothermal and Chemodynamic Anti-Infective Therapy.

Given the challenge of multidrug resistance in antibiotics, non-antibiotic-dependent antibacterial strategies show promise for anti-infective therapy. V2C MXene-based nanomaterials have demonstrated strong biocompatibility and photothermal conversion efficiency (PCE) for photothermal therapy (PTT). However, the limitation of V2C MXene's laser irradiation to the near-infrared region I (NIR-I) restricts tissue penetration, making it difficult to achieve complete bacterial eradication with single-effect therapeutic strategies. To address this, Pt nanoparticles (Pt NPs) are attached to V2C, forming artificial nanoplatforms (Pt@V2C). Pt@V2C exhibits enhanced PCE (59.6%) and a longer irradiation laser (NIR-II) due to the surface plasmon resonance effect of Pt NPs and V2C. Notably, Pt@V2C displays dual enzyme-like activity with chemodynamic therapy (CDT) and NIR-II enhanced dual enzyme-like activity. The biocatalytic mechanism of Pt@V2C is elucidated using density functional theory. In an in vivo animal model, Pt@V2C effectively eliminates methicillin-resistant Staphylococcus aureus from deep-seated tissues in subcutaneous abscesses and bacterial keratitis environments, accelerating abscess resolution and promoting wound and cornea healing through the synergistic effects of PTT/CDT. Transcriptomic analysis reveals that Pt@V2C targets inflammatory pathways, providing insight into its therapeutic mechanism. This study presents a promising therapeutic approach involving hyperthermia-amplified biocatalysis with Pt NPs and MXene nanocomposites.

Programmed Nanocloak of Commensal Bacteria-Derived Nanovesicles Amplify Strong Immunoreactivity against Tumor Growth and Metastatic Progression.

Recent discoveries in commensal microbiota demonstrate the great promise of intratumoral bacteria as attractive molecular targets of tumors in improving cancer treatment. However, direct leveraging of in vivo antibacterial strategies such as antibiotics to potentiate cancer therapy often leads to uncertain effectiveness, mainly due to poor selectivity and potential adverse effects. Here, building from the clinical discovery that patients with breast cancer featured rich commensal bacteria, we developed an activatable biointerface by encapsulating commensal bacteria-derived extracellular vesicles (BEV) with a responsive nanocloak to potentiate immunoreactivity against intratumoral bacteria and breast cancer. We show that the interfacially cloaked BEV (cBEV) not only overcame serious systemic side responses but also demonstrated heightened immunogenicity by intercellular responsive immunogenicity, facilitating dendritic cell maturation through activating the cGAS-STING pathway. As a preventive measure, vaccination with nanocloaked cBEVs achieved strong protection against bacterial infection, largely providing prophylactic efficiency against tumor challenges. When treated in conjunction with immune checkpoint inhibitor anti-PD-L1 antibodies, the combined approach elicited a potent tumor-specific immune response, synergistically inhibiting tumor progression and mitigating lung metastases.