Clear Zone Of Inhibition Research Articles

Evaluation of the antibacterial potential of mango (Mangifera indica) seed kernels in Bangladesh

Antimicrobial resistance is a global threat. On the other hand, Bangladesh produces high-quality mangoes, yet the mango coat and seed kernel, which contain medicinal components, remain unused. Therefore, this study investigated the antibacterial potential and toxicity of ethanol extracts from mango (Mangifera indica) seed kernels, which specifically target the bacterial strains Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Klebsiella sp. Amrapali variant mango seeds were collected, dried, ground into a fine powder, and extracted with ethanol at various ratios. The efficacy of the crude extract was tested via the disc diffusion method. The results demonstrated significant antibacterial activity against gram-positive bacteria (S. aureus and B. cereus), with clear zones of inhibition observed, especially in a dose-dependent manner. The pure crude extract inhibited the growth of S. aureus with a zone of 23 mm, identical to that produced by doxycycline. However, the extract exhibited limited activity against gram-negative bacteria (E. coli and Klebsiella sp.). Additionally, the extract was effective against multidrug-resistant S. aureus. The pure crude extract produced a 22.5 mm zone of inhibition against multidrug-resistant S. aureus, which was slightly smaller than that of gentamicin (23 mm) but larger than those of chloramphenicol (21 mm), vancomycin (20 mm), and tetracycline (16 mm). In vivo toxicity was assessed in mice, revealing no significant adverse effects on the hepatic structure or renal cortex at lower doses (100 μl of pure crude extract). However, higher doses caused mild histopathological changes in the liver and kidneys. These findings suggest that mango seed kernel extract holds promise as an alternative antibacterial agent, particularly against gram-positive and antibiotic-resistant bacteria, while being relatively safe at lower doses. Further research is needed to elucidate the active compounds, mechanisms of action, and broader applications of this extract in combating antibiotic-resistant bacterial infections.

Enhanced antibiotic degradation using rGO composites under visible light photocatalysis

A robust reduced graphene oxide (rGO), polyaniline (PANI) with calcium (Ca) and magnesium (Mg) bimetallic nanocomposite was successfully prepared using an in-situ chemical facial reducing method and named rGO@PANI-Ca:Mg. Various spectroscopic techniques, including XRD, SEM, TEM, XPS, and supplementary methods, were utilized to characterize the catalyst phase, microstructure, and optical attributes. The composite's photocatalytic efficiency was assessed by degrading antibiotics such as ciprofloxacin (CP) and tetracycline (TC) using calcium peroxide (CaO2) under visible light irradiation. The rGO@PANI-Ca:Mg composite demonstrates superior degradation efficiency for CP, 45 %, and for TC, 70 %, achieving a correlation coefficient R² of 0.94 and 0.991 respectively. This performance surpasses that of pristine GO, rGO, and rGO@PANI. The heightened photocatalytic activity is ascribed to forming a heterojunction, effectively mitigating electron-hole pair recombination. The incorporation of CaO2 promotes the generation of additional active reactive oxygen species (ROS), particularly OH·, ·O2−, e-, h+, as verified by radical scavenging experiments, indicating an enhancement in the degradation and a potential mechanism is also suggested. The degradation rate of TC, CP, and real wastewater (RW) is about 71 %, 45 %, and 40.98 %, respectively. The composite demonstrates stability and reusability for up to three catalytic cycles. Our experiments also showed that when bacteria were treated with a 2 mg catalyst, the minimum inhibitory concentration (MIC) was determined to be at a 10−3 dilution. This MIC value represents the lowest concentration at which the catalyst effectively inhibited bacterial growth, as evidenced by clear inhibition zones.

A multispecies bacterial-based direct-fed microbial alleviates Salmonella invasion and supports in vitro epithelial integrity.

Managing bacterial infections is of great importance in livestock production, particularly those caused by Salmonella enterica serovars Typhimurium or Dublin, which can impact both animal health and performance, as well as human food safety. Direct-fed microbials (DFM) can support gastrointestinal function and alleviate the potential negative effects of bacterial infections. In the present study, the capacity of a multispecies bacterial-based DFM containing Ligilactobacillus (formerly Lactobacillus) animalis 506, Propionibacterium freudenreichii 507, Bacillus licheniformis 809, and B. subtilis 597 to reduce S. Typhimurium ATCC14028 invasion was investigated using a co-incubation model with the HT29-MTX-E12 cell line (experiment 1). Next, a possible antagonistic effect of the DFM against S. Dublin ATCC 41286 was evaluated using an in vitro agar well diffusion method following a co-incubation of 48 h (experiment 2). At last, a series of experiments were performed to evaluate how different doses (6.25 × 106, 2.50 × 107, or 1.00 × 108 CFU/well) of the DFM would support the integrity of intestinal epithelial cells challenged or not with S. Typhimurium ATCC14028 or hydrogen peroxide under a transepithelial electrical resistance (TEER) assay with Caco-2 cells (experiments 3 and 4). In experiment 1, BDP significantly (P < 0.001) reduced by 90.8% the invasion of S. Typhimurium into HT29-MTX-E12 cells, whereas viability of the potentially harmful bacteria was reduced by 21.0% (P < 0.0001). In experiment 2, the antagonistic properties of BDP towards S. Dublin were confirmed by the detection of a clear inhibition zone (size = 8.6 mm). Lastly, without challenge, the lowest dose of the DFM (6.25 × 106 CFU) provided the greatest support to the cells (treatment × hour; P < 0.0001). However, when the cells were challenged with S. Typhimurium, all doses alleviated the loss of integrity caused by the pathogen (treatment × hour; P < 0.0001). In cells challenged with hydrogen peroxide, the greater dose (1.00 × 108 CFU) supported the cells for a longer period of time (treatment × hour; P < 0.0001). These in vitro findings set the stage for exploring the potential benefits of using a novel DFM as a promising tool and strategy to mitigate S. enterica infections in ruminants and improve animal health, food safety, and public health. Further, in vivo confirmation needs to be developed to validate these preliminary in vitro results.

Polyethylene glycol enhanced antibacterial activity of EDTA and ethyl maltol blended PLA against Staphylococcus aureus for biodegradable active packaging

Poly (lactic acid) (PLA) has limited promise as a bio-based antimicrobial packaging material due to its lack of plasticization, which limits antimicrobial agent release and antimicrobial efficiency. PLA were plasticized with polyethylene glycol (PEG) and blended with ethyl maltol or ethylenediaminetetraacetic acid (EDTA) as antibacterial agents by melt extrusion. The effects of combining PEG, EDTA, and ethyl maltol on sheet properties and antibacterial activity were investigated. Incorporation of ethyl maltol created a dense and smooth homogeneous surface, while EDTA addition caused large pores in the PLA sheet microstructure impacting swelling degree, water solubility and surface hydrophilicity. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) showed that both ethyl maltol and EDTA addition modified the amorphous and crystalline phases of plasticized PLA. FTIR results suggested interaction between the functional groups of PLA chains, PEG, ethyl maltol or EDTA which affected the glass transition temperature (Tg), degree of crystallinity, and thermal stability of PLA. Adding PEG into PLA-EDTA enhanced antibacterial activity against Gram-positive Staphylococcus aureus (reduction of 1.35 log CFU/mL from the initial inoculum). The higher water solubility of sheets corresponded to a suitable release rate and sufficient amounts of antimicrobial compounds against Staphylococcus aureus. In vitro antifungal testing, PLA-PEG-EDTA sheets did not exhibit a clear zone of inhibition but delayed Penicillium sp. spore formation until day 5 of incubation. PEG plasticized PLA sheets functionalized with ethyl maltol and EDTA showed potential as active biomaterials against food-borne pathogen bacteria Staphylococcus aureus.

Unveiling the power of TiO2 doped ZnO nanomaterial as an effective antimicrobial solution in the leather industry

The surface protection of leather supplies is a major concern worldwide due to its susceptibility to microbial growth. Different methods are employed to protect leather, their results ends up with the environmental pollution and human safety issues. Nanoparticles with excellent antimicrobial potential can provide sustainable protection to leather accessories. The present work represented a comprehensive investigation into the preparation and characterization of titanium dioxide-doped zinc oxide (ZnO/TiO2 NPs) nanoparticles and their exploring as a potential antimicrobial agent in the leather industry. ZnO nanoparticles were synthesized through Sol-gel method by the reduction of zinc acetate dihydrate via black cardamom seed's extract and subsequently doped with TiO2. The optical, structural, and morphological features of nanoparticles were thoroughly scrutinized through UV–visible spectroscopy, XRD, FT-IR, and SEM-EDAX. The UV–visible spectrum showed enhanced performance between 300 and 350 nm and various peaks of the FT-IR spectrum, i.e. 3315.53, 1566.20, 1402.25, 1340.53, 1014.56, 921.97, 690.52, and 677.01 cm−1, revealed chemical bonds that prove the correct doping of TiO2 in ZnO nanoparticles. The characteristic peaks obtained from XRD at 2Ө of 32°, 35.5°, 37.2°, 47.9°, 55.6° 63.51°, and 70° intimated to the crystal planes of (100), (002), (101), (102), (110), (103), and (112), respectively. SEM-EDAX images revealed the roughly spherical but agglomerated structure of nanoparticles with size 45.44 nm. Furthermore, minimum inhibitory concentration (MIC), antimicrobial potential, and anti-biofilm potential analyses of nanoparticles, against all selected microorganisms (Aspergillus niger, Staphylococcus aureus, and Escherichia coli) provided valuable insights into physical and biological properties of the nanoparticles. The clear zones of inhibition (29–30 mm) against these pathogenic strains showed exceptional antimicrobial action of the ZnO/TiO2 NPs. Overall, these results provide an approachable method to synthesize ZnO/TiO2 nanoparticles and their antimicrobial ability will prove to be beneficial for the protection of leather materials from various microbial contaminations.

Exploring a novel direct-fed microbial for ruminants to mitigate in vitro Salmonella invasion and infection

Abstract Managing bacterial infections is of great importance in cattle production, particularly those caused by Salmonella enterica serovars Typhimurium or Dublin, which can impact both animal health and human food safety. Direct-fed microbial (DFM) can support gastrointestinal health and alleviate potential bacterial infections. In the present study, the capacity of a bacteria-based DFM product [BOVAMINE DEFEND Plus; BDP; Novonesis, Denmark (BDP)] containing Lactobacillus animalis, Propionibacterium freudenreichii, Bacillus licheniformis, and B. subtilis to reduce Salmonella Typhimurium ATCC14028 invasion was investigated using the HT29-MTX cell line (Exp. 1) and also to evaluate the possible antagonistic effect against S. Dublin using an in vitro agar well diffusion method (Exp. 2). Briefly, in Exp. 1, after a 30 min pre-incubation with 1.0 ×108 CFU of BDP and/or 2.5 × 106 CFU of S. Typhimurium were added to each transwell. The quantity of S. Typhimurium invading the cells was measured after 90 min of co-incubation using CFU counts. As a control, the viability of the total S. Typhimurium was assessed to confirm the mode of action of BDP targets the pathogen invasion properties. In Exp. 2, the antagonistic efficacy of BDP against S. Dublin CHCC41286, isolated from cattle, was tested by adding BDP to wells in CLED agar plates casted with the pathogen above, zones of inhibition measured after 48 h incubation. In Exp. 1, BDP significantly (P &amp;lt; 0.05) reduced by 80.6 % the invasion of S. typhimurium into HT-29-MTX cells as well as from 16 % the viability of the pathogen. The antagonistic properties of BDP towards S. Dublin were confirmed by clear inhibition zones (8.6 mm). These two in vitro findings set the stage for exploring the potential benefits of using a novel DFM as a promising tool and strategy to mitigate Salmonella infections in ruminants and improve animal health, food safety, and public health. Further in vivo confirmation needs to be developed to validate these preliminary in vitro results.

Analysis of the Synergistic Effect of Antibiotics with Copper Oxide Nanoparticles Against Pseudomonas aeruginosa Isolated from Different Clinical Cases

Synergism between antibiotics and nanoparticles is one of the most important ways to combat antibiotic resistance. Copper nanoparticles were produced using a green, environmentally friendly method of mixing aqueous Ficus Sycomorus leaf extract with copper sulfate. The work aimed to study the synergistic effect of six antibiotics with copper oxide nanoparticles prepared in a green approach against bacteria Pseudomonas aeruginosa isolated from patient. A total of 110 specimens were collected from patients with burn, wound and urine infections. in Samarra General Hospital, Tikrit Teaching Hospital, Tikrit Military Hospital, and Baghdad Medical City of both genders from July to September 2023. A bacteriological examination was conducted to select bacterial pathogens, with a particular focus on Pseudomonas aeruginosa. From a total 110 cases, 50 (45.5%) gave positive cultures for Pseudomonas aeruginosa. CuO-NPs was characterized using different analytical techniques, Scanning Electron Microscope (SEM). showed that the CuO-NPs have a spherical shape, its average size is 29.2 nm. Energy-dispersive X-ray )EDX( results confirmed the presence of copper and oxygen in the composition. The synergistic effect of six antibiotics with CuO-NPs was studied. By evaluating the minimum inhibitory concentration of P. aeruginosa. The results show the highest inhibition against bacterial isolates was due to the synergistic effect of CuO-NPs with Impenem, Ciprofloxacin, Ceftazidime, Polymyxin B, Amikacin, and Cefepime respectively, especially on isolate (15) with zones of inhibition/mm were 19.33 ±0.33, 18.33 ±0.33, 16.33 ±0.33, 15.33 ±0.33, 14.67 ±0.33, and 12.7±0.58, respectively. The results indicated that the synergistic effect gave clear zones of inhibition against all isolates compared with the inhibition effect of nano-copper oxide and antibiotics.

Evaluation of MDR-specific phage Pɸ-Mi-Pa loaded mucoadhesive electrospun nanofibrous scaffolds against drug-resistant Pseudomonas aeruginosa- induced wound infections in an animal model

Given the escalating prevalence of drug-resistant wounds, there is a justified imperative to explore innovative and more efficacious therapies that diverge from conventional, ineffective wound healing approaches. This research has introduced a strategy to address multi-drug resistant (MDR) Pseudomonas aeruginosa infections in a chronic wound model, employing MDR-specific phage Pɸ-Mi-Pa loaded onto mucoadhesive electrospun scaffolds. A cocktail of three isolates of P. aeruginosa-specific lytic phages, Pɸ-Mi-Pa 51, Pɸ-Mi-Pa 120, and Pɸ-Mi-Pa 133 were incorporated into varying ratios of fabricated PCL-PVP polymer. These formulations were assessed for their therapeutic efficacy in achieving bacterial clearance in P. aeruginosa-induced wound infections. The study encompassed biological characterization through in vivo wound healing assessments, histology, and histomorphometry. Additionally, morphological, mechanical, and chemical analyses were conducted on the fabricated PCL-PVP electrospun nanofibrous scaffolds. Three clonal differences of the MDR P. aeruginosa-specific phages (Pɸ-Mi-Pa 51, Pɸ-Mi-Pa 120, and Pɸ-Mi-Pa 133) produced lytic activity and were seen to produce distinct and clear zones of inhibition against MDR P. aeruginosa strains Pa 051, Pa 120 and Pa 133 respectively. The average porosity of the nanofibrous scaffolds PB 1, PB 2, PB 3, and PB 4 were 12.2 ± 0.3 %, 22.1 ± 0.7 %, 31.1 ± 2.4 %, 28.0 ± 0.8 % respectively. In vitro cumulative release of MDR-specific phage Pɸ-Mi-Pa from the mucoadhesive electrospun nanofibrous scaffolds was found to be 70.91 % ± 1.02 % after 12 h of incubation after an initial release of 42.8 % ± 3.01 % after 1 h. Results from the in vivo wound healing study revealed a substantial reduction in wound size, with formulations PB 2 and PB 3 exhibiting the most significant reduction in wound size, demonstrating statistically significant results on day 5 (100 % ± 31.4 %). These findings underscore the potential of bacteriophage-loaded electrospun PCL-PVP nanofibrous scaffolds for treating drug-resistant wounds, generating tissue substitutes, and overcoming certain limitations associated with conventional wound care matrices.

Plant-endosymbiont mediated synthesis of silver nanobactericides with bioautography-guided partial purification of novel 1,2-benzenedicarboxylic acid, decyl octyl ester

In the present study, synthesis of silver nanobactericides was achieved from Curcuma longa L. and its endosymbiont for their antimicrobial activity. The nanobactericides exhibited notable antimicrobial potential against Escherichia coli and Staphylococcus aureus, as determined through broth dilution and minimum inhibitory concentration which ranged between 2.5 and 5 mg/mL. Characterization of nanobactericides revealed polydispersity with average size of 80 nm and crystalline nature showed distinct peaks. The Fourier transform infrared (FTIR) analysis revealed presence of exhibited peaks at 3362.24 cm⁻¹ (hydroxyl group), 1637.96 cm⁻¹ (carbonyl group), 1377.25 cm⁻¹ (alkane group), and 635.25 cm⁻¹ (alkyl group) which participated in the synthesis of nanobactericides. Endosymbiont crude extracts subjected to partial purification through thin-layer chromatography, and bioautography-guided fractionation identified an active compound at Rf 0.7 which showed clear zone of inhibition. The minimum inhibitory concentration of metabolite fraction was found to be 0.625 mg/mL against both the test pathogens. The dye degradation potential of nanobactericides was successful 81.27 % of degradation was achieved with safranin treated with silver nanobactericides from endosymbiont. Subsequently, nanobactericides synthesized from plants showed 59.88 % highest degradation with methylene blue. The profiling of metabolite was carried out with gas chromatography-mass spectrometry to identify as a novel metabolite, 1,2-benzenedicarboxylic acid, decyl octyl ester, showing antimicrobial potential against tested pathogens. The identified metabolite molecular formula was found to be C26H42O4 with molecular weight of 418. These promising results, especially for the scarcely reported compound, contribute to the understanding of plant-endosymbiont-synthesized nanobactericides with significant antimicrobial properties. The molecular analysis revealed the endosymbiont's affinity to Pseudomonas aeruginosa, and its sequence has been deposited in GenBank (Accession number OR984817). The study concludes with importance of nanobactericides from plant-endosymbiont consortium, highlighting their antimicrobial efficacy against human and phytopathogens.

FTIR, 1H, and 13C NMR Characterization and Antibacterial Activity of the Combination of Euphorbia Honey and Potato Starch.

In recent years, natural biopolymer (potato starch) hydrogels have been widely used in the field of wound dressing material. This study aimed to develop and characterize a novel antibacterial hydrogel made from potato starch and natural honey. The structure of the composite films was evaluated by Fourier transform infrared (FTIR) and 1H,13C nuclear magnetic resonance (NMR) spectroscopy, and the antibacterial activities were tested by agar diffusion method. FTIR analysis showed chemical interaction between the components of Euphorbia honey (EH) and potato starch hydrogel (PSH). The 1H-13C NMR and FTIR analyses of EH/PSH confirmed their structure and showed the presence of glucose and hydrocarbon derivatives. After 24 h of incubation, the EH/PSH hydrogel showed good antibacterial activity against three bacterial strains (K.pneumonia, P.mirabilis, and P. aeruginosa) by producing clear inhibition zones of 12.33 ± 1.88 mm, 15.33 ± 0.94, and 10 ± 0 mm, respectively. In addition, K. pneumonia, P. mirabilis, and P. aeruginosa were sensitive to the EH/SPH with a minimum inhibitory concentration (MIC) of 1 %. These results suggest that EH-PS has potential as an alternative candidate to conventional antibiotics.

Bioinspired Synthesis and Characterization of Dual-Function Zinc Oxide Nanoparticles from Saccharopolyspora hirsuta: Exploring Antimicrobial and Anticancer Activities.

Microbial synthesis offers a sustainable and eco-friendly approach for nanoparticle production. This study explores the biogenic synthesis of zinc oxide nanoparticles (ZnO-NPs) utilizing the actinomycete Saccharopolyspora hirsuta (Ess_amA6) isolated from Tapinoma simrothi. The biosynthesized ZnO-NPs were characterized using various techniques to confirm their formation and properties. UV-visible spectroscopy revealed a characteristic peak at 372 nm, indicative of ZnO-NPs. X-ray diffraction (XRD) analysis confirmed the crystalline structure of the ZnO-NPs as hexagonal wurtzite with a crystallite size of approximately 37.5 ± 13.60 nm. Transmission electron microscopy (TEM) analysis showed the presence of both spherical and roughly hexagonal ZnO nanoparticles in an agglomerated state with a diameter of approximately 44 nm. The biogenic ZnO-NPs exhibited promising biomedical potential. They demonstrated selective cytotoxic activity against human cancer cell lines, demonstrating higher efficacy against Hep-2 cells (IC50 = 73.01 µg/mL) compared to MCF-7 cells (IC50 = 112.74 µg/mL). Furthermore, the biosynthesized ZnO-NPs displayed broad-spectrum antimicrobial activity against both Pseudomonas aeruginosa and Staphylococcus aureus with clear zones of inhibition of 12.67 mm and 14.33 mm, respectively. The MIC and MBC values against P. aeruginosa and S. aureus ranged between 12.5 and 50 µg/mL. These findings suggest the potential of S. hirsuta-mediated ZnO-NPs as promising biocompatible nanomaterials with dual applications as antimicrobial and anticancer agents.

30종 에센셜오일Gardnerella vaginalis 및 Lactobacillus vaginalis에 미치는 항균효과 연구

Bacterial vaginosis (BV) is one of common diseases for women of childbearing age. Gardnerella vaginalis is often found in such vaginal infection, but it is not always possible to experience symptoms. This condition happens when the balance of microbiota which is detected in the vagina of healthy women of childbearing age breaks. It appears that the direct cause of the problem is a decrease in lactobacillus which keeps the vaginal pH acidic by producing lactic acid. The vagina is a muscular tube linked with mucous membranes. It is higher than any other skin parts in terms of permeability. Therefore, it is important to closely check the ingredients of frequently used feminine washes. This study attempted to investigate the effects of 30 different essential oils on Gardnerella vaginalis and examine if they obstruct the maintenance of Lactobacillus vaginalis among those which keep the vaginal environment slightly acidic, considering the fact that they are used to stay protected from external aggressors. Regarding disc diffusion, Gardnerella vaginalis was compared to Lactobacillus vaginalis in terms of the size of the growth inhibition clear zone. In addition, minimum inhibitory concentration (MIC) was measured, using the serial dilution technique, confirming the antimicrobial effects of Gardnerella vaginalis. The goal of this study is to provide basic data which are needed in developing safer feminine washes by finding essential oils which have no harm on the growth of Lactobacillus vaginalis.

Synergistic performance of biomedical textiles incorporated with cerium oxide carbon nanocomposites for the antibacterial and sunlight-driven photocatalytic activity of self-cleaning

This work inspects the antibacterial activity and sunlight-driven photocatalytic activity effect of nanocomposites of CeO2 and carbon as a surface coating onto the fabric with self-cleaning properties. The nanocomposites of CeO2 and carbon were confirmed by XRD, FTIR, Laser Raman and TEM, revealing the amorphous nature of carbon and the crystallographic structure of CeO2 nanoparticles. TEM depicted a sheet-like structure of carbon and orbicular morphology of CeO2. The nanocomposite was impregnated onto fabrics using an immersion and ultrasonication method. The fabrics impregnated with nanocomposites exposed a clear zone of inhibition of E. Coli and S.aureus bacterial strains, indicating potent bactericidal properties. The nanocomposite-impregnated fabrics show efficient and strong photocatalytic activity against P-Rosaniline Hydrochloride (PRH) dye, which was investigated at different concentrations of dye, repeatability, and reusability with time. The notable photocatalytic activity of the fabrics underscores their potential for use in anti-infection applications.

Development of silver-doped copper oxide and chitosan nanocomposites for enhanced antimicrobial activities.

Antimicrobial resistance (AMR) has emerged as a significant and pressing public health concern, posing serious challenges to effectively preventing and treating persistent diseases. Despite various efforts made in recent years to address this problem, the global trends of AMR continue to escalate without any indication of decline. As AMR is well-known for antibiotics, developing new materials such as metal containing compounds with different mechanisms of action is crucial to effectively address this challenge. Copper, silver, and chitosan in various forms have demonstrated significant biological activities and hold promise for applications in medicine and biotechnology. Exploring the biological properties of these nanoparticles is essential for innovative therapeutic approaches in treating bacterial and fungal infections, cancer, and other diseases. To this end, the present study aimed to synthesize silver@copper oxide (Ag@CuO) nanoparticles and its chitosan nanocomposite (Chi-Ag@CuO) to investigate their antimicrobial efficacy. Various established spectroscopic and microscopic methods were employed for characterization purposes, encompassing scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Subsequently, the antimicrobial activity of the nanoparticles was assessed through MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), and well-disk diffusion assays against Pseudomonas aeruginosa, Acinetobacter baumannii Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. The size of the CuO-NPs, Ag@CuO, and Chi-Ag@CuO NPs was found to be 70-120 nm with a spherical shape and an almost uniform distribution. The nanocomposites were found to possess a minimum inhibitory concentration (MIC) of 5 μg/mL and a minimum bactericidal concentration (MBC) of 250 μg/mL. Moreover, these nanocomposites generated varying clear inhibition zones, with diameters ranging from a minimum of 9±0.5 mm to a maximum of 25±0.5 mm. Consequently, it is evident that the amalgamation of copper-silver-chitosan nanoparticles has exhibited noteworthy antimicrobial properties in the controlled laboratory environment, surpassing the performance of other types of nanoparticles.

Antimicrobial Solid Starch-Iodine Complex via Reactive Extrusion and Its Application in PLA-PBAT Blown Films.

In this study, a solid masterbatch of starch-iodine complex with 6.7 wt.% iodine was prepared in pellet form using a ZSK-30 twin-screw extruder. Thermogravimetric (TGA) and isothermal TGA analysis of the pellets revealed that there was no significant loss of iodine due to sublimation during reactive extrusion. These solid pellets demonstrated antifungal properties when applied to strawberries via dip coating in an aqueous solution, extending their shelf life from two days to eight days, thereby reducing fungal growth and visual decay. Furthermore, the solid pellets displayed antibacterial activity against E. coli, as evidenced by the clear zone of inhibition observed in the Kirby-Bauer test. To enhance practical application, these pellets were further blended with PLA-PBAT film formulations at 10 and 18% by wt. to make blown films with effective iodine loadings of 0.7 and 1.3% by wt. These films showed superior antibacterial activity against E. coli compared with PLA control films and the commercial silver antimicrobial-containing films during direct inoculation tests as per ISO 22196. Tensile strength and elongation at break in machine direction (MD) for the starch-iodine-containing blown films were comparable to the control films in MD, but tensile strength was reduced to 37-40% in the transverse direction (TD). This was due to a non-uniform dispersion of the starch-iodine complex in the films, as confirmed by the visual and SEM analyses. Thus, this study illustrates the practical utility of the solid starch-iodine complex as a safe and efficient means of introducing iodine into an environment, mitigating the typical hazards associated with handling solid iodine.

Synthesis of Schiff Base through the Condensation Reaction Between Cellulose Dialdehyde with Ethylenediamine and Aniline as Well as Antibacterial Activity Test

Schiff base was created using a condensation reaction involving Ethylene diamine or Aniline and dialdehyde cellulose (DAC), which was obtained by oxidizing α-cellulose with sodium periodate as the oxidizing agent. The cellulose dialdehyde was identified through qualitative analysis, which involved observing the formation of a brick red sediment during the Fehling test and a rise in solubility in water. Additionally, the presence of an aldehyde group was confirmed by analyzing the FT-IR spectrophotometer data, which showed a peak at a wave number of 1635.64 cm-1. The synthesized dialdehyde cellulose has an oxidation degree of 80.9% and a carbonyl level of 10.36%. The Schiff base was analyzed using an FT-IR spectrophotometer, which revealed peaks at wave numbers 1635.64 cm-1 and 1604.77 cm-1. These peaks suggest the creation of a Schiff base bond (C=N) resulting from the condensation of the amine group from Ethylene diamine and Aniline with the aldehyde group from DAC. The antibacterial activity of Schiff bases was evaluated using the disc plate diffusion method. The Schiff base resulting from the condensation of DAC with Ethylenediamine at concentrations of 0.15%, 0.30%, and 0.45% was tested against S.aureus and E.coli. Clear zones of inhibition were seen, indicating the antibacterial effect. The Schiff base resulting from the condensation of DAC with Aniline at concentrations of 0.15%, 0.30%, and 0.45% showed clear zone diameters of 6.9 mm, 9 mm, and 12.5 mm against S.aureus and 7 mm, 12.5 mm, and 13 mm against E.coli. The clear zone diameters in a row were 10 mm, 10.8 mm, and 20.1 mm against S.aureus and 10.5 mm, 14.6 mm, and 17.1 mm against E.coli. The condensation of dialdehyde cellulose with ethylene diamine and Aniline leads to Schiff base formation. This Schiff base has antibacterial characteristics that are effective against S.aureus and E.coli.

Enhancing the photocatalytic and antimicrobial activity of ZnFe2O4 by composite with Ag2WO4 semiconducting material

In this research article, we have performed the degradation of methylene blue dye (MB) in the presence of ZnFe2O4/Ag2WO4 photocatalyst. These catalyst materials are prepared by a simple combustion method followed by a solution mixing method. The structure and morphology of prepared composite material are analyzed by using XRD, FTIR, UV-DRS, and scanning electron microscopy. The antimicrobial property of composite material is studied against E. coli and S. aureus food pathogenic bacteria. After the incubation time, the antimicrobial activity of the composite material shows a clear zone of inhibition. This composite photocatalyst is a promising material to increase the degradation percentage of MB (Methylene blue) dye in the presence of UV light. ZnFe2O4/Ag2WO4 composite material shows 72.72% degradation of the MB dye. The photocatalytic activity of composite material has been performed by varying the catalyst dosage and pH level of the medium used for the degradation process. The role of composite material in the degradation of dye and their increase in the reaction rate has also been discussed. From these results, the ZnFe2O4/Ag2WO4 composite is a good material to degrade the toxic pollutants in the environment.

An investigation of photocatalytic and biological properties of Croton bonplandianum-mediated Ag-Cu bimetallic nanoparticles

The green synthesis of nanoparticles using plant parts and their essence is considered an archetypal tactic in material synthesis for environmental beneficence. Multitudinous metal nanoparticles with potential bioactivities have been prepared based on plant extract. This study's main objective is synthesizing Ag-Cu bimetallic nanoparticles (Ag-Cu BMNPs) using leaf extract of Croton bonplandianum L (CB). Furthermore, its photocatalytic, antibacterial, anti-fungal, and anti-tuberculosis activities are systematically investigated in detail. The surface morphology of the prepared sample is shown to be highly porous, with an average grain size of ∼ 16 nm. The FTIR spectra exhibited that the phytomolecules from CB leaf extract serve as a capping and reductantfor forming Ag-Cu BMNP. Brunauer-Emmitte-Teller (BET) comprehends the CB leaf extract to be an active, cost-effective, reusable, and high surface area catalyst. The sample exhibited improved photocatalytic activity with an efficiency of 92.31 % at the moderate catalyst dose of 30 mg against methylene blue (MB) dye. Ag-Cu BMNPs exhibited a 17 mm inhibition zone at higher concentrations against both gram (+ve) and gram (−ve) bacterial strains. Also, the synthesized Ag-Cu BMNPs produced a clear inhibition zone of 16 mm and 15 mm at lower concentrations. The anti-fungal activity against A. flavus and C. albicans at higher and lower concentrations produced a clear inhibition zone of 17 mm,15 mm, and 6 mm, 9 mm, respectively. In addition, the anti-tuberculosis activity against Mycobacteria tuberculosis exhibited good results at a 0.4 µg/mL concentration for the synthesized sample. Moreover, Ag-Cu BMNPs enhanced their biological ability and did not increase their cytotoxicity, which provides a potential for the clinical applications of Ag-Cu BMNPs. In general, the suggested method for producing Ag-Cu bimetallic nanoparticles is successful in combating microbiological diseases.

An injectable, chitosan-based hydrogel prepared by Schiff base reaction for anti-bacterial and sustained release applications

Injectable hydrogels, providing sustained release as implanted materials, have received tremendous attention. In this study, chitosan-based hydrogels were prepared via Schiff base reaction of the aldehyde groups on Poly(NIPAM-co-FBEMA) and the amine groups on chitosan. Owing to the dynamic covalent linkage, the SC/PNF hydrogels exhibit pH-responsive, reversible sol-gel transition, injectable, and self-healing capacity. The mechanical strength of SC/PNF hydrogels can be operated simply by switching the composition or solid content of Poly(NIPAM-co-FBEMA) copolymers. Rheological analyses, including frequency sweeps, strain sweep scanning, and dynamic time sweeps, were employed to demonstrate the relationship between storage modulus (G′), loss modulus (G″), and composition of the SC/PNF hydrogels. In vitro release behaviors reveal that vancomycin-loaded SC/PNF hydrogel could contribute to both the initial burst release (over 1000 ppm within 4 h) and the sustained release (3000 ppm for at least 30 days). Pristine SC/PNF hydrogel holds good biocompatibility toward L929 cells and S. aureus that it degrades as incubated with S. aureus. However, vancomycin-wrapped SC/PNF hydrogel possesses a rapid bacterial-killing effect with a clear inhibition zone. In short, the SC/PNF hydrogels deliver not only sustainable release ability but also tunable physical properties, which are expected to be an outstanding candidate for non-invasive, anti-infection applications.

Iron-Based Nanoparticles Synthesis, Characterization, and Antimicrobial Effectiveness

Background: Antimicrobial resistance (AMR) has emerged as a significant and pressing public health concern, posing serious challenges to effectively preventing and treating persistent diseases. Developing new antibiotics with different mechanisms of action is crucial to effectively address challenges in treating infections. A lot of work has already been done on mono-metallic nanoparticles to address the issue.Methods: This study aimed to synthesize multi-metallic iron, silver, and chitosan-embedded nanoparticles using a green approach. Iron, silver, chitosan nanoparticles, and a composite of iron–silver–chitosan was also synthesized. The synthesized nanoparticles and composites were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier Transform Infrared Spectroscopy (FTIR) to evaluate their structural parameters. Their antimicrobial efficacy was investigated through MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), and well-disk diffusion assays against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans.Results: The size of the Cu-NPs, Cu-Ag NPs, and Cu-Ag-CS NPs were found to be in the range of 32-40 nm size with a spherical shape. The nanocomposites' MIC and MBC were calculated to be 125 μg/mL and 500 μg/mL, respectively. The nanocomposites exhibited a range of clear inhibition zones, with a minimum diameter of 12 ± 0.5 mm and a maximum diameter of 22 ± 0.5 mm. Conclusion: The iron–silver–chitosan nanocomposite has been shown to have significant antimicrobial effects in the laboratory environment compared to other nanoparticles hence can be applied as potential biomedical/biological candidates in future.Keywords: Antibacterial; Antifungal Agents; Iron; Silver; Chitosan; Nanoparticles