High Antibacterial Activity Research Articles

Clay minerals-mediated removal of Norfloxacin and Norfloxin-resistant bacteria from water environments and associated mechanisms.

Norfloxacin (NOR) is frequently detected in various water bodies and has the potential to promote the proliferation of NOR-resistant bacteria/genes in the environment. Efficiently removing residual NOR and NOR-resistant bacteria from contaminated water is critical to mitigating their environmental risks. This study investigated the ability of two common clay minerals, kaolinite and montmorillonite, to remove NOR and NOR-resistant bacteria from five different water environments (ultrapure water, simulated and real freshwater, and simulated and real seawater) and explored the underlying removal mechanisms. The results showed that both clays adsorbed NOR according to a pseudo-first-order kinetic model. In simulated and actual freshwater and seawater, the adsorption of NOR by kaolinite was 0.199, 0.120, 0.094, and 0.010mgg-1, while montmorillonite adsorbed NOR at significantly higher levels, with values of 2.880, 2.208, 0.433, and 0.067mgg-1, respectively. The primary mechanisms of adsorption included electrostatic interactions, cation exchange, and cation bonding and bridging. In addition to NOR sorption, culture tests revealed that montmorillonite exhibited significant antibacterial activity against NOR-resistant bacteria, achieving an inhibition ratio of 83.84 ± 4.01% when the initial concentrations of bacteria and montmorillonite were 1.68 ± 1.00 × 105CFU·mL-1 and 40mgmL-1, respectively. Remarkably, montmorillonite maintained its high sorption capacity and antibacterial activity even after multiple reuse cycles. These findings highlight the promising application potential of montmorillonite, particularly in terms of its storage and long-distance distribution capabilities, making it an effective material for removing both NOR and NOR-resistant bacteria from the environment. However, it is important to note that under estuarine conditions, clay-bound NOR could be released if water quality changes. Therefore, we conclude that strategies to degrade and remove antibiotics adsorbed onto clay minerals should be developed to prevent the release of antibiotics when clay particles enter the ocean, thus avoiding further environmental contamination.

Nutritional and Bioactive Compounds, Antioxidant Properties and Antibacterial Activity of Chinese Chive (Allium odorum L.).

The present study was conducted to generate the comprehensive data on the nutritional composition, minerals, heavy metal, bioactive compounds, antioxidant and antibacterial properties of Chinese chive (Allium odorum L.) grown at two different locations including Manipur and Punjab. The crop grown in Manipur exhibited higher values of nutritional and phytochemical compound values than those grown in Punjab. It exhibited significantly higher amounts of crude protein, crude fiber, potassium, calcium and iron content in the Manipur environment. The allicin content in leaves of Chinese chive on a dry weight (dw) varied from 1.31 to 1.4% and there was non-significant difference in allicin content at both locations. Besides, the heavy metal content of Chinese chive was much below the permissible limits of the World Health Organization. The IC50 value of Chinese chive was 78.908-95.140µg/ml which imparts strong antioxidant activity and higher DPPH (2,2-diphenyl-1-picrylhydrazyl)radical scavenging activity higher in fresh leaves than dried leaves. Total phenol and total flavonoid were found to be significantly high. In addition, high antibacterial activities were observed against toxin producing pathogenic bacterial strains of Staphylococcus aureus and Enterococcus faecalis. The nutritional and bioactive compounds, antioxidant properties and antibacterial activity of Chinese chive make it ideal for its use as a functional food and/or supplement.

Polysiloxane-Based Composite Coatings with Bactericidal Additives

This paper examines the effect of both natural and synthetic additives of different concentrations to a polysiloxane matrix in order to obtain bactericidal composites. Natural additives such as black cumin, cloves, and turmeric were compared with silver, a well-known antiseptic, and with graphene, which has potential bactericidal properties. The first stage of the research included the production of polysiloxane composites with the above-mentioned powders in the form of bulk solid samples, and then a series of tests were carried out on them to not only assess their bactericidal properties but also determine their effect on physicochemical properties such as chemical structure, surface wettability, roughness, hardness, and surface morphology. Based on the obtained results, the most promising composite recipes were selected, and coatings were produced from them on a super-smooth substrate, which had been previously cleaned using a plasma chemical method. The obtained results indicated that all obtained materials were characterized by high bactericidal activity. The conducted studies also showed a significant effect of the introduced additives on the mechanical properties of the polysiloxane matrix, including graphene, which improved the hardness of the composites. Plasma chemical modification of the substrates increased the adhesion of the tested coatings to them. In addition, the effect of the used additive was also visible in this area.

Antimicrobial and Antibiofilm Activity of Green Synthesized Silver Nanoparticles by Using In Vitro Grown Aloe vera L.

In this study, invitro grown Aloe vera L. tissues were used for AgNP synthesis. Adventitious root and callus tissues were grown in MS medium containing 1 mg/L IAA and 1 mg/L NAA. Using A. vera L. leaf, in vitro grown callus, and adventitious roots tissue extracts, AgNPs were synthesized. According to DLS analysis, PDI values and zeta potential values showed that AgNPs from adventitious root were more suitable in terms of size and surface charge. Characterization of adventitious root-derived AgNPs was performed by UV-Vis absorption spectrum, ICP/MS, SEM, FTIR, and XRD. According to HPLC results, catechin, gentisic acid, caffeic acid, coumaric acid, polydatin, coumarin, and ellagic acid were found in adventitious roots. Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC2 7853), MRSA (ATCC 33951) and Staphylococcus aureus (ATCC 6538) strains were used to determine the antibacterial and antibiofilm activity of AgNPs. The highest antibacterial activity was determined against P. aeruginosa. Lower concentrations of AgNPs caused changes in the structure of the biofilm formed by P. aeruginosa, which produced particularly strong biofilms, resulting in failure of biofilm maturation. Accordingly, AgNPs synthesized from Aloe vera L. adventitious roots had antibacterial and antibiofilm activity even at low concentrationsagainst the tested bacterial strains.

A Study of Chemical Composition and Bioactivity of Folk Medicinal Plant (Teucrium polium)

Introduction: Investigating the chemical composition and bioactivity of Teucrium polium, sometimes referred to as Germander, was the goal of the current study. Analysis was done on the T. polium extracts. Numerous chemical components found in it contribute to its therapeutic qualities. Flavonoids, terpenoids, essential oils, and other substances with antioxidant and anti-inflammatory qualities are among these chemicals. Material and Methods: Collected a sample of the leaves and bark of the Teucrium polium plant from the vicinity of the University of Tabuk and produced an extract for analysis. Gas chromatography was used to evaluate the extracts, and Teucrium polium extract's antibacterial qualities were also examined. Results: The ethanol extract outperformed the hexane extract in terms of activity or in other words Hexane extract was less active than ethanolic extract on all other microorganisms. The hexane extract exhibited a 23 mm inhibitory zone and high antibacterial activity against Escherichia coli. Despite this, the extracts' zones of inhibition for Pseudomonas aeruginosa and Escherichia coli were comparable in size (23, 24, and 23 mm, respectively). Conclusion and Work's Significance: The clinical, pharmacological, and research in medicine sectors, along with the food as well as cosmetics industries, can all benefit from the substantial biological activity of T. polium extracts. They possess a vast array of therapeutic applications and have long been used to cure a range of ailments.

Evaluation of the Antibacterial and Cell Culture Properties of Anodic Porous Alumina Prepared in Concentrated H2SO4.

The antibacterial activity of anodic porous alumina (APA) prepared using phosphoric, oxalic, and sulfuric acids was tested, and it was found that APA prepared using sulfuric acid had the highest antibacterial activity against Staphylococcus aureus and Escherichia coli. In addition, the results of the antibacterial test using APA prepared with different concentrations of sulfuric acid showed that APA prepared in concentrated sulfuric acid exhibited significantly higher antibacterial activity. APA formed in concentrated sulfuric acid also showed excellent antibacterial activity even at a high culture medium concentration, at which bacterial cells tend to multiply easily. Trace amounts of Al and S that leached out to the culture medium from APA prepared in concentrated sulfuric acid did not affect the antibacterial activity of APA, indicating that the APA surface exhibits excellent antibacterial activity. It was shown that the surface of APA prepared in concentrated sulfuric acid had excellent culture properties for fibroblasts while exhibiting antibacterial activity. APA prepared in concentrated sulfuric acid can be used in various applications that require excellent antibacterial activity as well as on surfaces that suppress bacterial growth and selectively cultivate target cells.

Effect of in vitro simulated gastrointestinal digestion on the antibacterial properties of bovine lactoferrin.

The aim of this research was to investigate the ability of an in vitro simulated gastrointestinal digestion (SGID) to generate peptides from bovine lactoferrin (LF) that possess antibacterial activity. Escherichia coli was examined as the target pathogen due to its prevalence in foods and the well-documented antibacterial effect of both LF and LF peptides against this organism. Results showed that in-vitro digested LF, specifically gastric LF digesta, exhibited significant antibacterial activity at low concentrations against E. coli compared to its undigested counterpart. Additionally, the highest antibacterial activity in the gastric digesta was associated with a relatively high molecular weight fraction of >30 kDa obtained within the first 30 min of the SGID. This demonstrates that the digestive process can result in the generation of antibacterial LF peptides and contribute to improving the antimicrobial properties of LF exhibited in its undigested state, making it a suitable dairy food additive to potentially provide protection against bacterial pathogens within the gastrointestinal system.

Antimicrobial Potential of Tinospora Cordfolia (Willd.) Miers (Menispermaceae) Against Disease-Causing Clinical Bacterial Pathogens

Tinospora cordifolia is an important plant growth herb belonging to the family Menispermaceae. It is a climbing deciduous and succulent shrub considered traditional medicine in Ayurveda. It has various sources of bioactive compounds and medicinal properties that produce great varieties of secondary metabolites with a broad spectrum of biological activities. It is well known for its nutraceutical food that provides health benefits mainly due to the phytochemicals present in the plant such as alkaloids, flavonoids, proteins, and carbohydrates. It has a wide application in pharmacological research such as antitumor, antiinflammatory, Cerebro-protective, cardio-protective, immunoregulatory, Vasorelaxation, and anxiolytic. Tinospora cordifolia showed antimicrobial activity against a few pathogenic bacteria and pathogenic fungi but not many clinical bacterial pathogens and hospital-acquired infections. In this study, the author focused on the antimicrobial activity of Tinospora cordifolia against eight clinical pathogenic bacteria (Escherichia coli, Klebsiella pneumoniae, MRSA, Proteus mirabilis, Salmonella typhi, Shigella sonnei, Pseudomonas aeruginosa, Acinetobacter baumanii) isolated mainly from patient’s sample. T. cordifolia was extracted from two different solvents, methanol and water. The antimicrobial activity was determined using an agar well diffusion assay. T. cordifolia extract has antibacterial activity against all tested clinical bacterial pathogens and has the highest antibacterial activity against Salmonella typhi in all ratios of methanol concentrations (47.5μg/ml). The Minimum Inhibitory Concentration (MIC) of Tinospora cordifolia methanol extract was found at 100μg/ml. Methanol solvent concentration with the most active antibacterial activity of the extract was of different concentrations as 300μg/ml followed by 450μg/ml and 500μg/ml.

Native and cationic cellulose nanofibril films enriched with avocado seed compounds as a green alternative for potential wound care applications

Cellulose nanofibrils (CNF) show great potential for skin wound care and healing due to their biocompatibility, non-cytotoxicity, and high swelling with good mechanical stability. In the presented study, for the first time native and cationized cellulose nanofibrils were used in combination with avocado seeds extracts obtained with different extraction methods (ASE), as an alternative to a well-known antibiotic, Clindamycin, to produce films with high and long-lasting antimicrobial efficacy. The swelling capacity of prepared films and extracts/antibiotic release kinetics were studied at different pH values to evaluate pH response behavior.All developed films exhibited high bacteriostatic and bactericidal activity against Gram-negative Escherichia coli and G-positive Staphylococcus aureus, resulting in up to 100 % bacterial reduction with the log reduction factor up to 5.64 or 6.50, at 14.2 mg of avocado seed extract or clindamycin integrated in the 1 cm2 of CNF film. The high swelling capacity (up to 65.67 %) and stability of avocado seed extracts-enriched CNF films provide a suitable moisture environment and a sustainable release (up to 40.98 % in 48 h) of bioactive compounds. The prepared antibacterial films' chemical and morphological characteristics and pH-responsive behavior proved the potential applications in the cosmetics, biomedicine, and pharmaceutical industry.

Chitosan-gelatin composite hydrogel antibacterial film for food packaging

Antibacterial hydrogel film can serve as food packaging materials to prevent bacteria growth and spread, thereby extending shelf life and improve food safety. In this study, an efficient antibacterial hydrogel film (CLG) was prepared with chitosan, lysine, and gelatin. The light transmission of the CLG hydrogel film was over 80 % in the visible region, facilitating the observation of chicken breast storage conditions. Additionally, the swelling ratios of the hydrogel films decreased with increasing gelatin concentration, from 145.7 g/g (CLG1) to 92.6 g/g (CLG2) and 81.5 g/g (CLG3). This reduction was attributed to the denser network structure formed by the interaction between gelatin and the CL polymer. The Scanning Electron Microscopy (SEM) showed that the water-absorbed CLG hydrogel had a unique sponge shape. Moreover, the CLG hydrogel film exhibits high antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In a practical storage experiment, the CLG hydrogel film extended the shelf life of chicken breast by up to 4 days compared to untreated samples, while effectively reducing total volatile basic nitrogen (TVB-N) levels. This hydrogel film is expected to become a promising food packaging material.

Enhancing the solubility and antibacterial activity of novel molecular salts of enrofloxacin drug with isomeric pyridinedicarboxylic acids

Enrofloxacin (EFX) is a third-generation synthetic fluoroquinolone with a broad spectrum of antibacterial activity but suffers from low water solubility, affecting its bioavailability. This study attempts to enhance the physicochemical and biological properties of enrofloxacin by converting it into multicomponent forms using crystal engineering concepts. Cocrystallization of enrofloxacin with isomeric pyridine-2,n-dicarboxylic acids (n = 3,4,5,6) resulted in four new crystalline salts (1:1): EFX·Py2,3DCA, EFX·Py2,4DCA, EFX·Py2,5DCA·H2O and EFX·Py2,6DCA·H2O; two of these are monohydrates. The protonation of the nitrogen atom of the piperazine moiety and the presence of crystallization water molecules were confirmed by single-crystal X-ray diffraction and Fourier transform infrared spectroscopy. Thermogravimetric analysis provided information on the thermal behaviour of multicomponent forms. The biological studies showed that the obtained salts are characterized by high antibacterial activity against Gram-positive and Gram-negative bacteria, and their haemolytic activity is low. The new salts demonstrate significantly greater solubility in water compared to the parent drug, along with enhanced antibacterial activity; hence, pyridinedicarboxylic acids appear to be efficient cocrystallizing agents for improving the efficacy of pharmaceutical ingredients.

Cell-Penetrating Peptide Induced Superstructures Triggering Highly Efficient Antibacterial Activity.

To endow non-antibacterial molecules with highly efficient bactericide activity is an important but challenging issue. Herein, a kind of cell-penetrating peptide octa-arginine (R8) is found to be effective in activating antibacterial ability when assembling with anionic surfactant sodium dodecyl sulfate (SDS), while individual R8 or SDS shows poor or no antibacterial ability. By combined electrostatic, hydrogen bond, and hydrophobic interactions, R8 and SDS associate into wormlike micelle and lamellar structure by forming supramolecular self-assembling units, depending on their charge ratio (CR). The lamellar aggregates show particularly high antibacterial activities against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Interestingly, E. coli and S. aureus are killed by membrane-disrupting and membrane-penetrating mechanisms, respectively. Furthermore, in vivo experiments evidence that the R8/SDS lamellar aggregates accelerate the recovery of bacteria-infected wounds, wherein the reduced inflammation and promoted angiogenesis are clearly presented. This study proves that highly efficient bactericidal activity is triggered by the synergistic action of penetrating peptide and anionic amphiphiles, thus providing a new strategy to realize highly efficient and targetable antibacterial application.

Synthesis and Characterization of Two Sparfloxacin Crystalline Salts: Enhancing Solubility and In Vitro Antibacterial Activity of Sparfloxacin

Background: To improve the solubility and permeability of Sparfloxacin (SPX) and enhance its antimicrobial activity in vitro, two unreported pharmaceutical crystalline salts were synthesized and characterized in this paper. One is a hydrated crystal of Sparfloxacin with Pimelic acid (PIA), another is a hydrated crystal of Sparfloxacin with Azelaic acid (AZA), namely, SPX-PIA-H2O (2C19H23F2N4O3·C7H10O4·2H2O) and SPX-AZA-H2O (4C19H23F2N4O3·2C9H14O4·5H2O). Methods: The structure and purity of two crystalline salts were analyzed using solid-state characterization methods such as single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and infrared spectroscopy. Additionally, the interaction characteristics between two crystal salt molecules were examined by constructing Hirshfeld surfaces and mapping specific real-space functions through Hirshfeld surface analysis. The solubility under physiological conditions, diffusivity across simulated biological membranes, and in vitro antibacterial activity against specific bacterial strains of two crystalline salts were evaluated using established assays, including minimum inhibitory concentration (MIC) tests. Results: Single-crystal X-ray diffraction and Hirshfeld surface analysis indicate that SPX forms stable crystal structures with PIA through charge-assisted hydrogen bonds N1-H1e···O10 (1.721 Å, 173.24°), N5-H5a···O11 (1.861 Å, 169.38°), and with AZA through charge-assisted hydrogen bonds N5-H5B···O8 (1.810 Å, 154.55°), N4-H4B···O6 (1.806 Å, 174.97°). The binding sites of two crystalline salts were at the nitrogen atoms on the piperazine ring of SPX. Compared with SPX, the equilibrium solubility of the two crystalline salts was improved by 1.17 and 0.33 times, respectively, and the permeability of the two crystalline salts was increased by 26.6% and 121.9%, respectively. In addition, SPX-AZA-H2O has much higher antibacterial activity on Pseudomonas aeruginosa and Bacillus subtilis than SPX. Conclusions: This research yielded the successful synthesis of two crystalline salts of Sparfloxacin (SPX), significantly improving its solubility and diffusivity, and bolstering its antibacterial efficacy against targeted bacterial species. These breakthroughs set the stage for innovative advancements in the realm of antimicrobial drug development.

Sustainable Smart Packaging from Protein Nanofibrils.

Smart packaging technologies are revolutionizing the food industry by extending shelf life and enhancing quality monitoring through environmental responsiveness. Here, a novel smart packaging concept is presented, based on amyloid fibrils (AM) and red radish anthocyanins (RRA), to effectively monitor food spoilage by color change. A protein nanofibrils biofilm is developed from whey protein, which is functionalized with RRA to endow the resulting films with advanced monitoring capabilities. A comprehensive characterization, including pH responsiveness, water vapor permeability, thermal and mechanical testing, and colorimetric responses, demonstrates the superiority of AM/RRA films compared to control films based on whey monomer building blocks. The findings indicate that the AM/RRA films can effectively monitor, for example, shrimp freshness, showing visible changes within one day at room temperature and significant alterations in color after two days. Furthermore, these films exhibit high antibacterial and antioxidant activities, reinforcing their suitability for efficient food packaging. By integrating bio-based materials from whey and natural anthocyanins, this research presents a biodegradable, sustainable, and cost-effective smart packaging solution, contributing to eco-friendly innovations in food preservation.

Heterophase CuO/Cu/Fe nanoparticle incorporated polyurethane coating for combating catheter-induced infection

To combat biofilm formation on the surface of medical devices, a new coatings based on polyurethane filled with heterophase nanoparticles CuO/Cu/Fe composition have been developed. Due to the synergistic antibacterial effect of the nanoparticle constituents, the obtained coatings demonstrated exceptional antibacterial activity. Thus the coating containing 5 % wt. or more of the CuO/Cu/Fe nanoparticles was at least 99.99 % against bacteria S. aureus, A. bumannii, K. pneumonia, P. aeruginosa. For this coating, the value of surface energy was maximum, indicating an increase in its hydrophobicity. The operational life of the catheter samples was more than 30 days, which exceeds the operational life of standard urinary catheters. Based on the results obtained, the application of the developed coating is a promising strategy for solving the catheter-associated urinary tract infection problem. Good biocompatibility was determined in vitro using 3T3 fibroblast cell culture, which is highly sensitive to toxic effects. Compared to other strategies of catheter surface modification, the use of polyurethane coating with nanoparticles of complex composition has a number of advantages: high antibacterial activity of nanoparticles due to the synergistic effect of constituents; biocompatibility of the coating provided by the use of biometals; long-term service life due to good adhesion of the coating to the standard silicon Foley catheter. Thus, the proposed coating containing nanoparticles effectively prevents bacterial colonization on catheters or other implants, thereby reducing the risk of postoperative catheter-induced infection.

Antibacterial activity of the biogenic volatile organic compounds from three species of bamboo.

Plant biogenic volatile organic compounds (BVOCs) possess ecological functions in antimicrobial benefits and air purification. The objectives of the study were to determine the differences in antimicrobial capacity of bamboo forests at different sampling sites. Three common bamboo species-Phyllostachys edulis, Bambusa emeiensis, and Phyllostachys violascens-were selected to determinate the antimicrobial activity of bamboo forests as well as under ex vivo conditions. Natural sedimentation method was used to determine the microbe counts in bamboo forests, and the microbe counts in grassland in the same area was measured as control treatment. The results showed that except for the P. violascens in Ya'an, the airborne microbial content of the sampling sites in bamboo forests was significantly lower relative to that of grassland in the same area, and inhibition rate reached 74.14% in the P. violascens forest in Dujiangyan. P. edulis forest and P. violascens forest in Ya'an had significantly lower inhibition rates than the other sampling sites, and there was no significant difference in the inhibition rates among the rest of the bamboo forest. The bacterial inhibition rate of bamboo leaves under ex vivo conditions varied with bamboo species and bacterial strains, with higher antibacterial activity against Gram-negative bacteria overall. Escherichia coli was sensitive to B. emeiensis leaves, while Staphylococcus aureus and Bacillus subtilis were sensitive to P. violascens leaves. Moreover, Candida albicans, S. cremoris, and Shigella Castellani were sensitive to P. edulis leaves. An analysis of the BVOCs composition from P. edulis collected in Changning by SPME-GC/MS revealed that the relative content of ocimene was obviously higher than other components. This study showed that P. edulis BVOCs have strong inhibitory ability to the tested microorganisms, and its main constituent, ocimene, has health benefit. P. edulis has the potential to become a forest recreation bamboo species.

Isolation and characterization of phytochemicals from leaf extract of Memecylon lushingtonii Gamble and their evaluation for biological properties

Memecylon lushingtonii Gamble (MLG) belongs to the Melastomataceae family and is used in Ayurvedic and Siddha medicine. Several Memecylon species have been recorded to be utilized by tribal in the treatment of various maladies. This plant is not explored scientifically except for the preliminary phytochemicals, antioxidant, and antimicrobial activities in the methanol leaves extract (Sivu et al., 2013). Discovery of new phytochemicals may help in drug discovery. The present study was an attempt to determine the phytochemical constituents in MLG leaves ethyl acetate (EtOAc) extract and to isolate bioactive compounds and evaluate their potential therapeutic applications. Ethyl acetate extract was evaluated for total phenolics and flavonoids; phytochemical constituents, antibacterial and antioxidant activities. Further, bioactive compound from 4th fraction of column chromatography was isolated and characterized by HPLC,LC-MS and H1NMR. The results indicated 37.5 µg/mL of phenolics, 60 µg/mL of flavanoids and twenty-one bioactive compounds by GCMS– analysis. The extract demonstrated considerable antibacterial activity with different concentrations like 50, 100 and 150 µg against Staphylococcus aureus, Bacillus licheniformis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. Highest antibacterial activity was found against K.pneumoniae (Zone of inhibition was 11 mm) at 150 µg .In addition, the EtOAc extract displayed free radical scavenging activity (IC50= 39.83 µg/ml). The isolated compound from 4th fraction of column chromatography was characterized as a triterpenoid, ursolic acid. In conclusion, our findings show that M. lushingtonii Gamble leaf EtOAc extract contains triterpenoid, ursolic acid, and also, many types of active compounds with therapeutic activities, particularly antibacterial and free radical scavenging activity.

Eco-Conscious Approach to Synthesizing Aluminum Oxides Using Nonthermal Plasma Technology

AlO is a prevalent oxide compound composed of aluminum and oxygen, with the chemical formula Al2O3. This study aims to prepare aluminum oxide nanoparticles using aluminum nitrate nonahydrate Al(NO[Formula: see text] 9H2O through direct exposure to a plasma jet system using argon gas, as plasma is the fourth state of matter and a common effective method. The major study in the preparation of Al2O3 nanoparticles, which is a physical method, examines the effect of aluminum oxide nanoparticles against bacteria and fungi. Different methods were used for diagnosis. The X-ray diffraction examination showed an average particle size of 37.8 nm. It was also found through the UV-Vis examination that a surface plasmon resonance was formed at 300 nm with an energy gap value of 4.21 eV. The electron microscope field emission scanning (FE-SEM) was used to study the surface morphology. The results of biological testing showed that aluminum oxide nanoparticles have high antibacterial and antifungal activity.

Electrospun lignin-loaded artificial periosteum for bone regeneration and elimination of bacteria

Recently, the non-negligible role of the periosteum in bone repair has attracted the attention of researchers. In this study, poly(ε-caprolactone) (PCL)/lignin nano-fibrous membranes prepared by electrospinning are proposed as an artificial periosteum. Both in vitro and in vivo studies confirmed that PCL/lignin membranes have a pro-osteogenic effect. This effect was dependent on the lignin concentration, and there was an optimal concentration at which the membrane possessed the highest osteogenesis-potentiating activity among those tested in this study. In addition, the PCL/lignin membranes exhibited promising antibacterial properties against both E. coli and S. aureus, with high lignin concentrations corresponding to high-bactericidal activity. The prepared PCL/lignin membranes displayed promising osteogenic and antibacterial properties. With satisfactory hydrophilicity and mechanical properties, they hold great potential in serving as an artificial periosteum for bone tissue repair. This study provides both theoretical and laboratory evidence for the application of the renewable resource lignin in the repair of the periosteum and bone injuries.

Anchoring atomic Pd on molybdenum disulfide with state-of-the-art specific activity in the electrochemical dehalogenation of florfenicol

The widespread discharge of halogenated organic pollutants (HOPs) in wastewater brings significant risks to the environment and human health due to potent high toxicity, antibacterial activity, and strong biodegradation resistance. Adsorbed atomic hydrogen (H*ads)-mediated electrocatalytic hydrodehalogenation (EHDH) has been recognized as an efficient strategy for HOPs removal through selectively breaking carbon-halogen bonds. In this work atomic Pd uniformly anchored on molybdenum disulfide (denoted as Pd-MoS2) was synthesized through a facile hydrothermal method and found with state-of-the-art specific activity in florfenicol (FLO) removal via the H*ads-mediated EHDH process. Pd-MoS2 completely dehalogenated (∼100 %) FLO within 30 min at a rate constant of 0.15 min−1, which was 6.0, 6.5 and 33.1 times the value of MoS2, Pd/C and carbon paper samples, respectively. Notably, the toxicity of the wastewater was reduced to 1/6 of its original value after the treatment. Moreover, Pd-MoS2 presented superior catalytic stability in five successive cycles. Furthermore, Pd-MoS2 was also robust in complex water environment with practical applicability for industrial wastewater treatment. A dual-active-center mechanism with enhanced H*ads production capacity and the improved H*ads utilization efficiency was contributed to the increased EHDH activity on Pd-MoS2.