Antibacterial Properties Research Articles

In vivo assessment of topically applied silver nanoparticles on entire cornea: comprehensive FTIR study

Silver nanoparticles (AgNPs) have gained attention in medicine for their potent antibacterial, antiviral, and anti-inflammatory properties. The use of silver nanoparticles in ophthalmic solutions raises concerns regarding potential toxicity of nanoparticles to ocular tissues, such as the cornea, conjunctiva, and retina, which necessitates further toxicity assessments aiding in the development of safer ophthalmic solutions. This study investigates the impact of AgNPs on corneal tissue using ophthalmic investigations, Fourier transform infrared (FTIR) spectroscopy, and chemometric analyses. Three concentrations of AgNPs (0.48 µg/mL, 7.2 µg/mL, and 15.5 µg/mL) were topically applied twice daily for 10 days, synthesized biologically by reducing silver nitrate with almond kernels water extract. Corneas, obtained by cutting 2–3 mm below the ora serrata, were analyzed with FTIR spectroscopy and subjected to chemometric analyses. Results reveal AgNPs’ influence on constituents with OH and NH groups, affecting corneal lipids and reducing the lipid saturation index. AgNPs alter both bulk and interfacial water, leading to changes in corneal hydration thus modifying corneal physico-chemical properties. The influence extends to the water environment around proteins and lipids, releasing bound water from phospholipids and disrupting hydrogen bonding networks around proteins. In conclusion, the applied AgNPs concentrations can be linked to dry eye onset.

Gold Nanoparticles: Multifunctional Properties, Synthesis, and Future Prospects

Gold nanoparticles (NPs) are among the most commonly employed metal NPs in biological applications, with distinctive physicochemical features. Their extraordinary optical properties, stemming from strong localized surface plasmon resonance (LSPR), contribute to the development of novel approaches in the areas of bioimaging, biosensing, and cancer research, especially for photothermal and photodynamic therapy. The ease of functionalization with various ligands provides a novel approach to the precise delivery of these molecules to targeted areas. Gold NPs’ ability to transfer heat and electricity positions them as valuable materials for advancing thermal management and electronic systems. Moreover, their inherent characteristics, such as inertness, give rise to the synthesis of novel antibacterial and antioxidant agents as they provide a biocompatible and low-toxicity approach. Chemical and physical synthesis methods are utilized to produce gold NPs. The pursuit of more ecologically sustainable and economically viable large-scale technologies, such as environmentally benign biological processes referred to as green/biological synthesis, has garnered increasing interest among global researchers. Green synthesis methods are more favorable than other synthesis techniques as they minimize the necessity for hazardous chemicals in the reduction process due to their simplicity, cost-effectiveness, energy efficiency, and biocompatibility. This article discusses the importance of gold NPs, their optical, conductivity, antibacterial, antioxidant, and anticancer properties, synthesis methods, contemporary uses, and biosafety, emphasizing the need to understand toxicology principles and green commercialization strategies.

Chemical Components and Antibacterial Properties of Essential Oil from Zingiber densissimum

Chemical Components and Antibacterial Properties of Essential Oil from Zingiber densissimum

Preparation and Antibacterial Properties of Poly (l-Lactic Acid)-Oriented Microporous Materials

In this manuscript, an efficient self-reinforcing technology—solid hot drawing (SHD) technology—was combined with green processing supercritical carbon dioxide (SC-CO2) foaming technology to promote poly (l-lactic acid) (PLLA) to form an oriented micropore structure. In addition, Polydimethylsiloxane (PDMS), with a high affinity of CO2 and biological safety, was introduced to enhance the nucleation effect in SC-CO2 foaming and co-regulate the uniformity of oriented micropores’ structure. The results showed that orientation induced PLLA crystallization, so the tensile strength was improved; the maximum tensile strength of the oriented micropores’ PLLA reached 151.2 MPa. Furthermore, the micropores mainly improved the toughness; the maximum elongation at break reached 148.3%. It is worth mentioning that PDMS can form an antibacterial film on the surface of the material, so that the material has a continuous antibacterial effect.

Preparation and Characterization of Ozonated Liposomes Loaded with Curcumin: A Potential Approach for Diabetic Retinopathy Treatment

Background: Limitations in drug penetration are overcome by nanotechnology, particularly liposomes, which enhance targeted administration of ocular medications. Liposomes can augment the therapeutic effects of curcumin, a natural compound with positive impacts on the retina. Treatments for eye diseases can also benefit from the antibacterial properties of ozonated oil liposomes. Objectives: This study aims to develop and evaluate ozonated liposomes loaded with curcumin for ocular drug delivery applications, specifically targeting diabetic retinopathy (DR). Methods: Liposomal nanoparticles were prepared using thin-film hydration, incorporating phospholipids, lecithin, cholesterol, ozonated oil, and curcumin. We assessed physicochemical properties including particle size, zeta potential, encapsulation efficiency (EE), and morphology. Drug release profiles and stability studies were also conducted. Results: The optimized liposomes showed a particle size of 84.77 nm, a zeta potential of -16.8 mV, and an EE of 94.73%. The formulation exhibited sustained curcumin release over 24 hours, reaching 82.09% cumulative release. Stability studies indicated minimal changes in key parameters over three months at room temperature. Conclusions: The developed ozonated liposomal formulation demonstrates promising characteristics for curcumin delivery, potentially enhancing its therapeutic efficacy in ocular applications, particularly for DR.

Lavender and Black Pine Waste as Additives Enhancing Selected Mechanical and Hygrothermal Properties of Cement Mortars

The paper presents the mechanical and hygrothermal properties of cement mortars containing bio-powders made from lavender waste and black pine wood. The wastes were mechanically ground with a hammer mill to a fraction not exceeding 0.5 mm and then dried in air-dry conditions. The influence of bio-additives in amounts of 1.5% and 2.5% of the overall mortar volume was tested. The aim of the paper was to determine the impact of bio-additives on the mechanical and hygrothermal properties of the tested cement mortars. This publication included tests of compressive and flexural strength, elastic modulus, water absorption, absorption due to capillary rise, sorption and desorption properties, thermal properties, microstructural tests using mercury intrusion porosimetry and SEM, and EDS. The main conclusions of the research indicate that mortars with both 1.5% and 2.5% bio-powders are characterized by strong bactericidal properties, lower sorption properties at high air humidity, lower thermal conductivity, reduced compressive strength by 22–27%, no significant effect on the flexural strength, and significant reduction in capillary action of mortars both with short-term and long-term water exposure.

Investigating the effect of fermentation byLactobacillus reuteri on biochemical properties of Ceylon Cinnamon

Abstract Introduction Fermentation is an important biotechnological process that improves the biochemical properties of natural raw materials by transforming high molecular compounds into more beneficial low molecular compounds through microbial biotransformation. Ceylon cinnamon (Cinnamomum zeylanicum Blume), globally recognized as 'true cinnamon', contains high molecular weight, complex compounds that are responsible for its renowned antioxidant, antibacterial, and therapeutic properties, making it a vital component in medicinal applications1. Aims The present study aimed to investigate the effect of fermentation by Lactobacillus reuteri on selected phytochemical contents, antioxidant, and antibacterial properties of bark extracts of Ceylon cinnamon (Cinnamomum zeylanicum Blume) and to determine the optimum conditions for fermentation of Cinnamon bark extract by L. reuteri. Method Authenticated Ceylon cinnamon bark (CCB) was extracted into water using the decoction method. The water extract was fermented by L. reuteri under controlled conditions (pH 6, incubation at 35 ºC) and optimized using two parameters; the inoculum density (1.5×108 cfu/ml and 7.5×108 cfu/ml) and incubation time (2 and 4 days). After fermentation, total polyphenolic content (TPC), total flavonoid content (TFC), DPPH free radical scavenging activity and antibacterial activity of non-fermented extracts (NFE) and fermented extracts (FE) of CCB were evaluated. Antibacterial activity was determined using the agar well diffusion method against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Ethical approval was not required since no human or animal study was done during the study. Results The extract fermented with an inoculum density of 7.5×108 cfu/ml and incubated for 4 days showed the highest TFC (19.3 ± 0.3 mg RE/g) and antioxidant activity (IC50: 97.2 ± 0.8 µg/ml) in comparison to that of NFEs (TFC:13.3 ± 0.3 mg RE/g and DPPH activity: IC50: 233.7 ± 12.8 µg/ml). Moreover, the fermented samples showed a reduction in TPC, indicating possible biotransformation of compounds. and no significant change in the antibacterial activity in comparison to the non-fermented samples. Discussion and Conclusion This study was mainly focused on investigating the effect of fermentation of Ceylon cinnamon bark aqueous extract by Lactobacillus reuteri. The increased antioxidant activity and total flavonoid content are notable and could be attributed to chemical transformations of some complex flavanols including catechin gallate and epicatechin gallate present in aqueous cinnamon to catechin and epicatechin monomers by the action of enzymes secreted by L. reuteri during the fermentation process2. Hence, this study suggests that fermentation using L. reuteri has a considerable positive impact on certain biochemical properties of cinnamon water extract. Cinnamon bark is a complex matrix containing various phytochemicals that could interact with bacterial strains in ways that are not fully understood. These interactions could lead to unexpected effects or limitations during fermentation.

A Review on Biological Activity of Quinoline-based Hybrids

Abstract: The quinoline scaffold has gained attention for its potential applications in organic synthesis and the medical field.The objective has been to identify quinoline-based hybrids with a range of biological activities, including as anti-tuberculosis, anti-cancer, antimalarial, anti-inflammatory, anti- Alzheimer's, antibacterial, and antidiabetic properties. This review provides a critical overview and highlights the latest development of quinoline-based hybrids and their potential bioactivities.

Preliminary Exploration of the Protective Mechanism of Eugenol Against Acute Liver Injury Induced by Thioacetamide Based on Metabolomics

Acute liver injury (ALI) is a significant global public health issue that can rapidly develop into acute liver failure, seriously endangering the safety of patients. Eugenol has various pharmacological effects such as antioxidant, anti-inflammatory, antibacterial, and neuroprotective properties. Through pathological section observation, eugenol can alleviate the degree of liver damage caused by thioacetamide. Based on metabolomics, a total of 87 metabolites were found to have differences in content between the control group and the thioacetamide group. Compared with the control group, the contents of 42 metabolites had increased and 45 metabolites had decreased in the thioacetamide group. These differential expressed metabolites mainly indicate inflammatory damage, oxidative damage, and abnormal energy metabolism. There were 269 metabolites with differences in content between the eugenol intervention group and the thioacetamide group. Compared with the thioacetamide group, there were 101 metabolites with increased content and 168 metabolites with decreased content in the eugenol intervention group. These differential expressed metabolites suggest that eugenol intervention can correct inflammation damage, oxidative damage, and energy metabolism abnormalities caused by TAA. This study found through pathological section observation and metabolomics that eugenol has a protective effect on acute liver injury caused by thioacetamide, and the protective mechanism may be related to the antioxidant and anti-inflammatory effects of eugenol.

The Use of Thyme (Thymus vulgaris) Essential Oil for Controlling Cercospora Leaf Spot (Cercospora beticola) on Sugar Beets (Beta vulgaris)

Decreasing efficacy of fungicides and the withdrawal of further hazardous active ingredients in pesticides from use have prompted the search for alternative methods of crop protection. Essential oils (EOs) are secondary metabolites of plants and have been proven to show antibacterial, antifungal, and pest-repellent properties. This study was undertaken to determine the activity of grapefruit, rosemary, pine, sage, and thyme EOs against the fungus Cercospora beticola, which is the most dangerous pathogen of sugar beet and the causal agent of Cercospora leaf spot. According to the determined Minimum Inhibitory Concentration (MIC), thyme EO was found the most effective against C. beticola. For most of the fungal isolates tested, the MIC of this EO was 0.313 mL/L. Thyme EO also inhibited the growth of multi-resistant isolates. Based on the results obtained, thyme EO was subjected to further testing in field conditions, where its efficiency in controlling C. beticola was also proven. The results indicate that the use of thyme EO may be a promising method for the protection of sugar beets, although it requires further optimization in the context of its inclusion in sustainable protection programs assuming a reduced number of synthetic fungicide treatments.

In Situ Forming Injectable Gelatin-Based Antibacterial Bioadhesives for Preventing Postoperative Leakage and Abdominal Adhesions.

Postoperative anastomotic leakage (AL) and abdominal adhesions are two major complications after intestinal surgery, with an incidence of 2-25% for AL and 93% for adhesion. Until now, there is no method addressing AL and abdominal adhesions simultaneously. In this work, Bi-PEG-succinimidyl succinate (PEG-NHS), amino-gelatin (Agel) is combined with cefoperazone-sulbactam (SCF) to prepare a multifunctional bioadhesive (SCF/SEAgel) for the postoperative leakage and adhesion prevention. SCF/SEAgel possesses a great sealing capability for tissue, with a bursting pressure of 54kPa. The loaded SCF endows the systems with good antibacterial properties. The in vivo antiadhesion experiments show that SCF/SEAgel possesses better anti-adhesion properties than the commercially used sodium hyaluronate gel. In the cecum leakage model, the SCF/SEAgel effectively seals the leakage with a survival rate of 100%, superior to commercial products (Sainaoning). Meanwhile, it significantly reduces tissue adhesion. Finally, the laparoscopic surgery with dogs shows that the SCF/SEAgel can be injected through minimally invasive surgery, demonstrating its ease of use. Combined with its great biocompatibility, SCF/SEAgel is very promising in intestinal surgery.

Antibacterial double-layer calcium phosphate/chitosan composite coating on metal implants for tissue engineering

In this study, four different promising two-layer composite coatings on titanium substrates with antibacterial properties were investigated. Two different types of antibacterial agents were used to impart antibacterial properties to the coatings: antibiotic amikacin (in three different concentrations) and zinc. Chitosan, which also has antibacterial properties, was used as a carrier layer for amikacin on a calcium phosphate coating incorporating zinc. This combination should enable long-term antibacterial properties of a bone implant and thus prevent potential complications during wound healing due to bacterial contamination. To examine the physico-chemical properties of the samples, the elemental, chemical and phase compositions, the thickness and the wettability of the coatings were investigated. The release of amikacin from the chitosan coatings was investigated using high-performance liquid chromatography. Antibacterial activity of the prepared coatings was evaluated against five hospital bacteria strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae) and one strain from the microbial strain collection (methicillin-resistant Staphylococcus aureus, ATCC 43300). To investigate the cell toxicity of the composite coating, cell adhesion, proliferation and osteogenic differentiation were tested with mesenchymal stem cells. According to the results, the composite coatings with an amikacin concentration of 5.0 and 7.5 percent by weight have the best biological and antibacterial properties.

A versatile natural gelatin-based hydrogel for emergency wound treatment through hemostasis, antibacterial, and anti-inflammation

Emergency wounds are often accompanied by bacterial infection, oxidative stress, and excessive inflammation due to the inability to quickly close and stop bleeding, resulting in chronic wounds that are difficult to heal. Clinically, surgical suturing is the fastest method for wound closure, but it is only suitable for wounds with small bleeding volumes and causes unsightly scar formation. Consequently, there is a critical need for hemostatic dressings versatile enough to address a spectrum of diverse and intricate wounds, especially in emergency scenarios. In this study, we constructed a unique versatile natural gelatin-based hydrogel with hemostasis, antibacterial, and anti-inflammation properties. The hydrogel was composed of 4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy) butyrylethylenediamine-modified methacrylated gelatin (GelMA-NB) and epigallocatechin gallate-grafted polylysine (EPL-EGCG), which imparts adhesion, antibacterial and antioxidant properties to the hydrogel. Simultaneously, the hydrogel was loaded with GelMA microspheres encapsulating natural resveratrol (RES@GM). This combination not only exhibited outstanding hemostatic capabilities but also preserved the anti-inflammatory potential of RES. In different animal models, the hydrogel exhibited outstanding hemostatic and wound healing effects, down-regulated the expression of IL-1βto promote inflammatory regulation and potential for angiogenesis and anti-scar. In conclusion, unique versatile natural gelatin-based hydrogel suitable for various complex wounds provides a promising strategy for emergency wound dressing applications.

Tuning the antioxidant and antibacterial properties of lignin by physicochemical modification during sequential acid precipitation from Kraft black liquor

Turning lignin from black liquor waste into value-added bioactive agents is one of the possible routes for improving the sustainability and profitability of lignocellulosic industry. However, due to chemical and structural variability of lignin, it is necessary to isolate specific lignin fractions from black liquor with the purpose to achieve samples with unique chemical and structural characteristics and therefore, specific biological activities. In this study, poplar lignin fractions isolated from Kraft black liquor by sequential acid precipitation at pH´s 7.5, 5 and 2.5 (denoted as P-7.5, P-5 and P-2.5) were characterized according to their physicochemical, antioxidant and antibacterial properties. In general, lignin fractions displayed a wide elimination of lateral chains (aryl-β ether and C–C) and, therefore a high phenolic content and low molecular weight, as the pH sequential precipitation was decreased from 7.5 to 2.5. Moreover, thermal analysis revealed that the P-7.5 lignin fraction showed higher thermal stability than P-2.5 and P-5. In terms of antioxidant activity, the P-7.5 lignin fraction, with a higher S/G ratio and a less oxidized structure compared to P-5 and P-2.5, exhibited higher antioxidant activity. In addition, lower antibacterial effect was observed for all lignin fractions against Escherichia coli compared to that obtained against Staphylococcus aureus. Among them, the P-2.5 and P-5 fractions, with higher phenolic content and lower molecular weight values than P-7.5, showed a greater antibacterial effect against S. aureus.

Biocompatibility and Antibacterial Potential of Tetrahedral Amorphous Carbon (ta-C) Coatings on CoCrMo Alloy for Articulating Implant Surfaces.

Premature implant failure, a critical concern in biomedical applications, is often attributed to poor biocompatibility and vulnerability to bacterial colonization. These issues are addressed by creating an endoprosthetic material with natural biocompatibility and antibacterial properties. In this invitro study, the relaxed and unrelaxed tetrahedral amorphous carbon (ta-C) coatings were examined, both fabricated by the improved patented Pulsed Laser Deposition (PLD) technology. The chemical composition, surface roughness, hardness, topography, and wettability were analyzed. The ta-C surfaces were incubated by MM6 cells, E. coli and S. capitis bacteria for 24 h. PCR assessed the inflammatory response in MM6 cells, while fluorescence microscopy quantified adhering bacteria, and scanning electron microscopy examined local adhesion behavior. The results demonstrate comparable carbon phase composition, wettability properties, and hardness for both relaxed and unrelaxed ta-C. However, relaxed ta-C coating exhibited significantly fewer defects in terms of both quantity and quality, along with an antibacterial effect against E. coli. This suggests that the relaxed ta-C coating could contribute to the development of an endoprosthesis, preventing adverse biological reactions and implant-related infections, thus improving the longevity of the prosthesis.

Design, Synthesis, Antibacterial, and Antifungal Evaluation of a New Series of Quinazoline - Thiazole and/or Quinazoline - Triazole Hybrids as Bioactive Heterocycles.

Herein, a one-pot reaction between cyclohexanone, thiourea, and 2,5-dimethoxybenzaldehyde allowed to prepare hexahydroquinazoline-2(1H)-thione4 firstly, which followed by reacting with hydrazine hydrate to produce the corresponding 2-hydrazinylhexahydroquinazoline 6. Interesting analogs of thiazolo[3,2-a]quinazoline 713 where obtained when hexahydroquinazoline-2(1H)-thione 4 reacted with 1,2-dibromoethane, chloroacetyl chloride, bromoacetic acid, bromoacetic acid/4-chlorobenzaldehyde, 2-bromopropionic acid, ethyl bromo cyanoacetate, and/or bromomalononitrile; respectively. While triazolo[4,3-a] quinazoline 14-16 were created when 2-hydrazinylhexahydroquinazoline 6 reacted with triethyl orthoformate, acetic anhydride, and carbon disulfide respectively. Numerous spectroscopy tests, including FT-IR, NMR (1H &13 C), and MS spectrum, proved all the newly produced analogs. Additionally, the new analogs were examined for their antibacterial and antifungal properties against Escherichia coli, Staphylococcus aureus, and Candida albicans. It was discovered that triazolo[4,3-a] quinazoline analogs 14-16 have superior bacterial and fungal activity when compared to the corresponding conventional doses of Streptomycin andGriseofulvin. Towards Candida albicans; compounds 14, 15, and 16 increase activity with 1.14 %, 1.15 %, and 1.21 %, respectively more than griseofulvin.While, for Staphylococcus aureus; compounds 14, 15, and 16 increase activity with 1.5 %, 1.5 %, and 1.7 %, respectively more than streptomycin. Morever, for Escherichia coli; compounds 14, 15, and 16 increase activity with 1.19 %, 1.21 %, and 1.22 %, respectively more than streptomycin. Finally, structure activity relationships show that quinazoline derivatives exhibit higher activity when fused to pyrazole ring 14-16 as compared when fused thiophene ring 7-13.

Preparation and properties of polytetrafluoroethylene/zinc oxide antibacterial filaments

AbstractThe potential of polytetrafluoroethylene (PTFE) products as surgical dressings is considerable, yet their absence of antibacterial properties substantially restricts their medical applications. To enhance the utility of PTFE in the medical sector, this research loaded nano zinc oxide (ZnO) particles into the PTFE filament matrix through a wet spinning process. This approach successfully yielded PTFE/ZnO composite filaments with antibacterial properties. The characterization results of the filaments show that when the mass ratio of PTFE to ZnO is 8:1, the filament has the best mechanical performance with a tensile strength of 6.78 MPa and an elongation at break of 274.46%. At the same time, composite antibacterial filaments under different process conditions show excellent antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with an antibacterial rate of over 99%. The excellent mechanical properties ensure the ability to further process single filaments, which can be woven into fabrics, textiles, and various other products. Therefore, the composite antibacterial filaments with excellent comprehensive performance prepared in this study are expected to be applied in the field of medical fabrics.Highlights Provide new solution ideas for functional PTFE composite filaments preparation. The prepared PTFE/ZnO composite filament has good acid and alkali resistance as well as excellent antibacterial properties, which is expected to broaden the application field of PTFE filaments.

The Effectiveness of Herbal Mouthwash with Mangosteen Peel Extract in Inhibiting Dental Plaque Formation

Abstract Objective Dental plaque control is important for preventing periodontal tissue diseases. Dental plaque control therapy is enhanced when supported by adjunctive therapy, including the use of mangosteen peel extract mouthwash. Mangosteen peel extract contains α-mangostin, saponins, alkaloids, tannins, flavonoids, quinones, and triterpenoids, which have antibacterial properties against bacteria that cause dental plaque. This study aims to determine the effectiveness of mangosteen peel extract mouthwash at concentrations of 2, 4, and 6% in inhibiting plaque formation. Materials and Methods The study used a quasi-experimental design with pre- and posttreatment examinations. Samples were taken using purposive sampling on 32 patients of Periodontology Clinic of Padjadjaran University Dental Hospital. The patients underwent prophylactic treatment (scaling), then the dental plaque index was measured using the Q-ray Cam Pro and the Loe and Silness Index before (day 1) and after (day 3) gargling with distilled water or mangosteen peel extract mouthwash at concentrations of 2, 4, and 6% for 2 days without oral hygiene in the maxillary area. The data were analyzed using the Wilcoxon test, analysis of variance (ANOVA), and the Kruskal–Wallis test. Results A phytochemical analysis revealed that the mangosteen peel extract contains antibacterial compounds such as flavonoids, saponins, polyphenols, quinones, and triterpenoids. The mangosteen peel extract mouthwash group exhibited lower mean differences in plaque index compared with the aquades group. The 2% mangosteen peel extract mouthwash shows the smallest mean difference of 0.25 in the Q-ray Cam Pro examination and 0.062 in the Loe and Silness Index examination. Conclusion Mouthwash with 2, 4, and 6% mangosteen peel extract has an effect in inhibiting dental plaque formation, with 2% concentration exhibiting the best inhibitory effect on dental plaque formation.

Antibacterial, Herbicidal, and Plant Growth-Promoting Properties of Streptomyces sp. STD57 from the Rhizosphere of Adenophora stricta

Bacterial wilt triggered by the soil-borne pathogenic bacterium Ralstonia solanacearum is one of the most serious diseases in tomato plants, leading to huge economic losses worldwide. Biological control is considered an environmentally friendly and sustainable way to manage soil-borne diseases. In this study, Streptomyces sp. STD57 isolated from the rhizosphere of Adenophora stricta showed strong antibacterial activity against R. solanacearum. Pot experiments showed that strain STD57 exhibited a significant biocontrol effect (81.7%) on tomato bacterial wilt in the greenhouse environment. Furthermore, strain STD57 could inhibit the growth of weeds (Amaranthus retroflexus, Portulaca oleracea, and Echinochloa crusgalli) but promote the growth of crops (wheat, rice, and tomato). The plant growth-promoting substance was identified as indoleacetic acid (IAA) by high-pressure liquid chromatography–mass spectrometry and genome analysis. Coarse separation of the fermented extracts revealed that the antibacterial and herbicidal substances were mainly in the fermentation supernatant and belonged to different products. These findings suggested that strain STD57 may be a potential biocontrol and bioherbicide agent useful in agriculture.

Electron-donable heterojunctions with synergetic Ru-Cu pair sites for biocatalytic microenvironment modulations in inflammatory mandible defects

The clinical treatments of maxillofacial bone defects pose significant challenges due to complex microenvironments, including severe inflammation, high levels of reactive oxygen species (ROS), and potential bacterial infection. Herein, we propose the de novo design of an efficient, versatile, and precise electron-donable heterojunction with synergetic Ru-Cu pair sites (Ru-Cu/EDHJ) for superior biocatalytic regeneration of inflammatory mandible defects and pH-controlled antibacterial therapies. Our studies demonstrate that the unique structure of Ru-Cu/EDHJ enhances the electron density of Ru atoms and optimizes the binding strength of oxygen species, thus improving enzyme-like catalytic performance. Strikingly, this biocompatible Ru-Cu/EDHJ can efficiently switch between ROS scavenging in neutral media and ROS generation in acidic media, thus simultaneously exhibiting superior repair functions and bioadaptive antibacterial properties in treating mandible defects in male mice. We believe synthesizing such biocatalytic heterojunctions with exceptional enzyme-like capabilities will offer a promising pathway for engineering ROS biocatalytic materials to treat trauma, tumors, or infection-caused maxillofacial bone defects.