Strong Antibacterial Activity Research Articles

Synthesis and characterization of new quaternized galactomannan derivatives with antibacterial activity.

The continuous increase in bacterial resistance requires the study and development of new biocompatible antibacterial materials. Galactomannan gum was extracted from endosperms of Dimorphandra gardneriana seeds, modified through quaternization reactions (with NaOH/CHPTAC), and evaluated for antimicrobial activity. Four quaternized derivatives were obtained (QG1-QG4). The derivatives were characterized by FTIR, NMR, and rheology, which confirmed the cationization. The galactomannan structure was theoretically studied, and Zeta potential exhibited positive increase in the charge of quaternized derivatives, changing from -3.2mV (unmodified galactomannan) to +59.35mV (QG4). Elemental analysis revealed an increase in degree of substitution (DS) between the derivatives, of which QG4 exhibited the highest DS (0.51). QG4 exhibited a bactericidal effect in the antimicrobial test for determination of minimal inhibitory and bactericidal concentrations, against Gram-positive bacteria. Atomic force microscopy showed an increase in bacterial cell surface roughness and decrease in cell height after treatment with QG4. QG3 and QG4 demonstrated antibiofilm potential, showing 50% and 40% of inhibition, respectively. After MTT assay, cell viability was maintained approximately 100% for all derivatives at concentrations of 20mg/mL on RAW 264.7 macrophages and 86% with 250μg/mL on L929 cells. Galactomannan was successfully modified, demonstrating strong antibacterial activity, concomitant to the increase in DS, Zeta potential and reduction of molar mass, with good biocompatibility. Therefore, this study presents a new material with potential for development of formulations for biomedical applications, from industrial waste, strengthening of the D. gardneriana production chain.

Antimicrobial dynamics and DNA nicking within 1,3-propanediaminium dibromide and dichloride supramolecular frameworks: The critical role of strong hydrogen bonding and subtle molecular interactions

Amine salt compounds are attracting increased attention due to their potential bioactive properties. This study explores the synthesis and detailed characterization of two novel amine salts, 1,3-propanediaminium dibromide (13DPBr) and 1,3-propanediaminium dichloride (13DPCl), through single-crystal X-ray diffraction, Hirshfeld surface analysis, and optical absorption spectroscopy. Structurally, 13DPBr crystallizes in the orthorhombic space group Pbcn, while 13DPCl crystallizes in the monoclinic space group P2/n. Supramolecular assemblies in both compounds are driven by strong N–H···X (X = Cl, Br) hydrogen bonds, alongside weaker C–H···X interactions. The optical absorption spectra indicated band gaps of 4.32 eV for 13DPBr and 4.56 eV for 13DPCl. The biological activities of these compounds were assessed through DNA nicking assays and antimicrobial tests. The antimicrobial properties were evaluated using agar diffusion assays against pathogenic bacterial strains, including Salmonella enterica, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The Minimum Inhibitory Concentration (MIC) results demonstrated that both salts exhibited strong antibacterial activity, with 13DPBr showing higher efficacy against Pseudomonas aeruginosa. DNA nicking assays using pUC19 plasmid DNA revealed that both compounds offered significant protection against hydroxyl radical-induced DNA damage, preventing the degradation of plasmid DNA. These results highlight the potential of 13DPBr and 13DPCl as promising agents for antimicrobial and DNA protection applications.

Evaluation of Physicochemical and Biological Properties of Chitosan Hydrolysate Produced by Microwave-Assisted Cellulase Hydrolysis

AbstractThis work estimated the biochemical nature of the enzymatic chitosan hydrolysate (CH) as oligomeric chitooligosaccharide products resulting from microwave-aided cellulase hydrolysis of chitosan from shrimp and crab as well as their biological effects and potential preservative application. The microwave irradiation was conducted at 125 W for 15 min simultaneously during the cellulase degradation of shrimp and crab chitosan, previously prepared by a 30-min microwave-aided deacetylation (86.7% and 82.7% degree of deacetylation), producing shrimp chitosan hydrolysate (SCH) and crab chitosan hydrolysate (CCH), respectively. The products SCH and CCH were tested for their solubility in distilled water, viscosity, molecular weight (Mw), FTIR, mass spectra, antioxidant, and antibacterial activities. The obtained SCH and CCH were incorporated into two food systems (yogurt and orange juice) at proportions of 0.08–0.12 g/100 mL as potential preservatives. The average Mw of SCH and CCH was 14.79 and 13.18 kDa, respectively, coupled in each case with 1–6° of polymerization (DP), strong antibacterial and antioxidant activities, and the capacity to dissolve in water in all proportions, becoming more soluble as weight decreased. The chemical, microbiological, and sensory changes in orange juice and yogurt were investigated at 0, 15, and 30 days of cold storage after being enriched with these ingredients. Over the 30-day storage period, the orange juice and yogurt showed enhanced physicochemical, microbiological, and sensory characteristics based on the content of chitosan hydrolysate. The study provided potentially a new and safe preservation technology for food systems.

An Innovative Use of Hydroxyapatite (HAp) from Pokea Clam Shells (Batissa violacea var. celebensis) for Toothpaste Manufacturing

Innovation research on the use of hydroxyapatite from pokea clam shells (Batissa violacea var. celebensis) for toothpaste manufacturing has been successfully conducted. This study aims to determine how to synthesize and characterize hydroxyapatite (HAp) from pokea shells and the efficiency of its use in making toothpaste. The research process was conducted through hydroxyapatite synthesis and hydroxyapatite toothpaste formulation. The success of this synthesis was proven by the characterization of XRF spectrophotometer, FTIR spectrophotometer and digital optical microscope. The results of XRF analysis showed that the CaO content in the material was 88.21%. The results of FTIR analysis showed that in hydroxyapatite material there was absorption at wave numbers 926 cm-1 and 1024 cm-1 which showed asymmetric strain vibrations and bending vibrations of PO43- groups. The results of XRD characterization of HAp show that the diffraction peak is at an angle of 2θ = 20-57 ° with a crystal size of 46.15 nm and a degree of crystallinity of 85.43%. Digital optical microscope test results at 500x and 1000x magnification, showed hydroxyapatite has a uniform and non-porous shape. The hydroxyapatite toothpaste produced is bone white in color with menthol aroma and slightly rough texture. The resulting toothpaste is homogeneous, the diameter of the distribution that meets the quality requirements of toothpaste is 6.833 cm. The pH measurement result on toothpaste is 5.82 which meets the toothpaste quality requirements. The result of viscosity measurement on toothpaste is 20,000 cpa.s which meets the requirements of toothpaste viscosity. The foam formed is 10 mm where the height of the foam formed has met the requirements. Hydroxyapatite toothpaste has good stability and strong antibacterial activity, where the clear zone formed is 18.7 mm

Bioactive Silk Revolution: Harnessing Curcuminoid Dye and Chitosan for Superior Antimicrobial Defence and UV Shielding

Background/Objectives: The use of natural colourants is gaining attention due to their biocompatibility and functional benefits. This study introduces a different approach using turmeric (Curcuma longa L.) dye extract combined with chitosan to significantly enhance the antibacterial and UV-shielding properties of silk. Methods: The turmeric dye’s chemical composition was analyzed using liquid chromatography mass spectrometry (LC-MS), UV–visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). The dyed silk’s colourfastness was tested through rubbing, washing, and light exposure. Results: The chitosan-mordanted silk showed strong antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as antifungal activity against Aspergillus niger (A. niger). It also demonstrated a high ultraviolet protection factor (UPF). For comparison, alum-mordant was used, and chitosan proved more effective. Beyond its use as a dye, turmeric is renowned for its medicinal properties. Its antioxidant, anticancer, and anti-inflammatory properties have been extensively researched, which are primarily linked to its curcuminoid compounds. Turmeric is used in traditional medication to treat digestive issues, arthritis, and skin diseases. Conclusions: This work underscores the innovative use of plant-based dye extracts and natural mordants like chitosan as a sustainable alternative to conventional metallic mordants, paving the way for the evolution of bioactive silk with improved functional properties.

Calotropis procera Mediated Synthesis of Silver Nanoparticles and its Antibacterial Effect on Selected Pathogens

This study investigates the green synthesis and antibacterial potential of silver nanoparticles (AgNPs) derived from Calotropis procera leaf extract. The AgNPs was characterized using Ultraviolet-Visible (UV-VIS) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM and TEM), Energy Dispersive X-ray (EDX) and X-ray Diffraction (XRD). The spectrum from UV-VIS had a peak centered at 445 nm confirming the formation of AgNPs, SEM-TEM micrographs showed them as aggregated, spherical in shape and about 15.30 – 17.66 nm in size, while EDX revealed Ag with highest proportion (75.56 %). The FTIR analysis revealed the presence of functional groups such as alcohols, ethers, esters, alkenes, carboxylic acid and amines. The XRD confirmed the crystalline nature of the synthesized CP-AgNPs. The synthesized AgNPs showed strong antibacterial activity against Escherichia coli (18.1±0.2 mm), Enterobacter sichuanensis (16.8±0.5 mm), Pseudomonas aeroginosa (14.4±0.3 mm), Staphylococcus aureus (22.2±0.5 mm) and Streptococcus agalactiae (21.5±0.1 mm). This study demonstrates an efficient, eco-friendly method for synthesizing AgNPs with strong antibacterial potential, which could be valuable for developing alternative antimicrobial agents.

Natural colourants from Sargassum polycystum C.Agardh (Phaeophyceae) for fabric dyeing: an eco-friendly method for textile colouring by response surface methodology

ABSTRACT Natural dyes have promising potential in the textile industry as a sustainable and eco-friendly alternative to synthetic dyes. In this study, a natural dye was extracted from the brown alga S. polycystum using a microwave-assisted extraction method under various extraction parameters. Response surface methodology (RSM), which combines transformational models and sequential technologies, was used in this study to improve the procedure. Response surface models were developed to correlate the extraction yield with four parameters, namely, algal concentration, pH of extraction medium, extraction time and temperature. Dyed and undyed wool fabrics were characterized by scanning electron microscope (SEM). The results demonstrated that the colour strength (K/S) of dyed wool increases by decreasing the pH, increasing the dyeing temperature, dye concentration and time of dyeing process. The optimal level of pH, dye concentration, dyeing temperature and time for obtaining the highest K/S was 2.3 g 50 ml‒1, 120°C and 15 min, respectively. Dyeing of wool fabric processed under the optimal conditions showed strong anti-bacterial and anti-fungal activity and good colour-fastness properties.

Antibacterial, Antioxidant and Cytotoxicity Assessment of Crassocephalum crepidioides Leaf Extract

The goal of the present investigation was to demonstrate the antibacterial activity of different solvent extracts (methanol, ethanol, cold aqueous and hot aqueous) of Crassocephalum crepidioides against ATCC bacterial cultures of Staphylococcus aureus, Escherichia coli, Methicillin resistant Staphylococcus aureus, Pseudomonas aeruginosa and its antioxidant potential. Furthermore, the chemical constituents present in the extract was perused by Gas chromatography-mass spectroscopy (GC-MS), along with in vitro cytotoxicity assessment. All the extracts were shown to be sensitive against S. aureus, MRSA and P. aeruginosa except for the ethanolic extract which was resistant to P. aeruginosa. Of all the extracts, hot aqueous extract found to be the most effective. It was found that Minimum inhibitory concentration (MIC) value of hot aqueous extract against S. aureus, MRSA and P. aeruginosa were 5 mg/mL, 5 mg/mL and 40 mg/mL, respectively. DPPH results showed that C. crepidioides leaf extract has potent antioxidant activity with IC50 value of 57.9 µg/mL. 22 compounds were detected in hot aqueous extract through Gas chromatography-mass spectroscopy. The results of the cytotoxicity evaluation displayed that the IC50 value of the hot aqueous extract of C. crepidioides on Vero cell lines was 292 µg/mL. This study concludes that C. crepidioides leaf extract is non-toxic, has various bioactive components and strong antibacterial and antioxidant activities, thus making it a promising therapeutic agent for various biomedical applications.

Isolation and Characterization of a Novel Escherichia Bacteriophage with Potential to Control Multidrug-Resistant Avian Pathogenic Escherichia coli and Biofilms.

Background/Objectives: Avian pathogenic Escherichia coli (APEC) infection is a significant problem for the global chicken industry, as it decreases animal welfare and is associated with substantial economic losses. Traditionally, APEC infections have been controlled through the use of antibiotics, which has led to an increased prevalence of antibiotic-resistant E. coli. Therefore, developing alternative treatments for APEC infection is crucial. Methods: In this study, an Escherichia phage specific to multidrug-resistant (MDR) APEC, designated as phage vB_EcoP_PW8 (phage vECPW8), was isolated. The morphology, phage adsorption to host cells, one-step growth curve, thermal stability, pH stability, whole-genome sequencing, antibacterial ability, and antibiofilm efficacy of phage vECPW8 were evaluated. Results: The results demonstrated that phage vECPW8 has a Podoviridae morphology and is effective at lysing bacteria. Phage vECPW8 exhibited a high absorption rate to bacterial cells (more than 85% within 10 min) and had a latent period of 20 min, with a burst size of 143 plaque-forming units per cell. Additionally, phage vECPW8 showed good temperature and pH stability. The phage displayed strong antibacterial activity in vitro, and its efficacy in controlling bacteria was confirmed through scanning electron microscopy. Whole-genome sequencing revealed that the phage has a linear genome with 69,579 base pairs. The genome analysis supported the safety of the phage, as no toxin, virulence, or resistance-related genes were detected. Phage vECPW8 was identified as a novel lytic phage in the Gamaleyavirus genus and Schitoviridae family. The phage also demonstrated antibiofilm efficacy by reducing and preventing biofilm formation, as evidenced by biofilm biomass and bacterial cell viability measurements. Conclusions: These results indicate that phage vECPW8 is a promising candidate for the effective treatment of MDR APEC infections in poultry.

Antibacterial Activity and Antifungal Activity of Monomeric Alkaloids.

Scientists are becoming alarmed by the rise in drug-resistant bacterial and fungal strains, which makes it more costly, time-consuming, and difficult to create new antimicrobials from unique chemical entities. Chemicals with pharmacological qualities, such as antibacterial and antifungal elements, can be found in plants. Alkaloids are a class of chemical compounds found in nature that mostly consist of basic nitrogen atoms. Biomedical science relies heavily on alkaloid compounds. Based on 241 papers published in peer-reviewed scientific publications within the last ten years (2014-2024), we examined 248 natural or synthesized monomeric alkaloids that have antifungal and antibacterial activity against Gram-positive and Gram-negative microorganisms. Based on their chemical structure, the chosen alkaloids were divided into four groups: polyamine alkaloids, alkaloids with nitrogen in the side chain, alkaloids with nitrogen heterocycles, and pseudoalkaloids. With MIC values of less than 1 µg/mL, compounds 91, 124, 125, 136-138, 163, 164, 191, 193, 195, 205 and 206 shown strong antibacterial activity. However, with MIC values of below 1 µg/mL, compounds 124, 125, 163, 164, 207, and 224 demonstrated strong antifungal activity. Given the rise in antibiotic resistance, these alkaloids are highly significant in regard to their potential to create novel antimicrobial drugs.

Fabrication of Multifunctional Green-Synthesized Copper Oxide Nanoparticles Using Rumex vesicarius L. Leaves for Enhanced Photocatalytic and Biomedical Applications

Recently, the use of plant extracts has emerged as an innovative approach for the production of various nanoparticles. Enhancing green methods for synthesizing copper oxide (CuO) nanoparticles (NPs) is a key focus in the field of nanotechnology. This study presents a novel and eco-friendly synthesis of CuO NPs using Rumex vesicarius L. leaf extracts, offering a cost-effective and efficient method. The synthesized CuO NPs were evaluated for their cytotoxic effects against human cervical carcinoma (HeLa) cells, as well as their photocatalytic and antimicrobial activities. The morphology, size, and structural properties of the CuO NPs were characterized using various analytical techniques. X-ray diffraction (XRD) analysis confirmed the pure crystalline structure of the CuO NPs with a size of 19 nm, while transmission electron microscopy (TEM) showed particle sizes ranging from 5 to 200 nm. The photocatalytic performance of the CuO NPs was assessed through the photodegradation of crystal violet (CV) and methylene blue (MB) dyes under UV light. The NPs exhibited excellent decolorization efficiency, effectively degrading dyes in aqueous solutions under irradiation. Furthermore, the green-synthesized CuO NPs displayed strong antibacterial and antifungal activities against a variety of human pathogens. They also demonstrated significant dose-dependent cytotoxicity against the HeLa cancer cell line, with an IC50 value of 8 ± 0.54 μg/mL.

Antibacterial and Photocatalytic Applications of Silver Nanoparticles Synthesized from Lacticaseibacillus rhamnosus.

The biosynthesis of silver nanoparticles (AgNPs) presents an innovative and sustainable approach in nanotechnology with promising applications in fields such as medicine, food safety, and pharmacology. In this study, AgNPs were successfully synthesized using the probiotic strain Lacticaseibacillus rhamnosus (BCRC16000), addressing challenges related to stability, biocompatibility, and scalability that are common in conventional nanoparticle production methods. The formation of AgNPs was indicated by a color change from yellow to brown, and UV-visible spectrophotometry confirmed their presence with a characteristic absorption peak at 443 nm. Furthermore, Fourier transform infrared (FTIR) spectroscopy revealed the involvement of biomolecules in reducing silver ions, which suggests their role in stabilizing the nanoparticles. In addition, field emission scanning electron microscopy (FE-SEM) showed significant morphological and structural changes. At the same time, dynamic light scattering (DLS) and zeta potential analyses provided valuable insights such as average size (199.7 nm), distribution, and stability, reporting a polydispersity index of 0.239 and a surface charge of -36.3 mV. Notably, the AgNPs demonstrated strong antibacterial activity and photocatalytic efficiency, underscoring their potential for environmental and biomedical applications. Therefore, this study highlights the effectiveness of Lacticaseibacillus rhamnosus in the biosynthesis of AgNPs, offering valuable antibacterial and photocatalytic properties with significant industrial and scientific implications.

Mucus-Penetrable Biomimetic Nanoantibiotics for Pathogen-Induced Pneumonia Treatment.

Bacterial pneumonia has garnered significant attention in the realm of infectious diseases owing to a surge in the incidence of severe infections coupled with the growing scarcity of efficacious therapeutic modalities. Antibiotic treatment is still an irreplaceable method for bacterial pneumonia because of its strong bactericidal activity and good clinical efficacy. However, the mucus layer forming after a bacterial infection in the lungs has been considered as the "Achilles' heels" facing the clinical application of such treatment. Herein, traceable biomimetic nanoantibiotics (BioNanoCFPs) were developed by loading indacenodithieno[3,2-b]thiophene (ITIC) and cefoperazone (CFP) in nanoplatforms coated with natural killer (NK) cell membranes. The BioNanoCFP exhibited excellent demonstrated mucus-penetrating abilities, facilitating their arrival at the infection site. The presence of Toll-like receptors in the NK cell membrane rendered the BioNanoCFP with the capability to recognize pathogen-associated molecular patterns within bacteria, allowing precise targeting of bacterial colonization sites and achieving substantial therapeutic efficacy. Overall, our findings demonstrate the viability and desirability of using NK cell membrane-mediated drug delivery as a promising strategy for precision treatment.

The Composition, Antioxidant and Antibacterial Activity of Essential Oils from Five Species of the Magnoliaceae Family.

The leaves of Magnoliaceae family plants contain abundant essential oils (EOs), and these species can be used in many fields due to their high industrial, medicinal, and ornamental values. This study aims to identify the main compounds of the EOs from the leaves of five common Magnoliaceae species (Michelia maudiae, Michelia hedyosperma, Michelia macclurei, Manglietia lucida, Manglietia conifer) using hydrodistillation, GC-MS analysis, and in vitro tests. Additionally, the antioxidant and antibacterial activities of the EOs were also evaluated. The results show that 151 compounds were identified across five species, with sesquiterpenes being dominant. Some key compounds (such as β-caryophyllene, δ-amorphene, β-guaiene, globulol, and β-acorenol) were common among all the species, highlighting their crucial roles in plant physiology and resilience. Other compounds (like valeranone and nerolidol in M. maudiae and β-elemene in M. macclurei) were specific, indicating different functions. Among the five species, the essential oil of M. macclurei contains β-elemene and nerolidyl acetate, and it has the weakest antioxidant activity (IC50 value: 2918.61~21,341.98 μg/mL) but the strongest antibacterial activity (inhibition zone diameter: 8.55 ± 0.93~22.92 ± 0.46 mm; LC50 value: 0.02~0.78 mg/mL). Meanwhile, the EO of M. maudiae demonstrated the best antioxidant activity (the IC50 value was 1283.58~6258.32 μg/mL) and the second-best antibacterial activity (the inhibition zone diameter ranged from 7.61 ± 0.02 to 26.92 ± 0.46 mm, and the LC50 value was 0.03~2.28 mg/mL). Overall, the EO of M. maudiae had the best comprehensive performance. Therefore, the EOs of M. macclurei and M. maudiae showed different performances in biological activity categories, and they could be developed and used in different fields, with the possibility of discovering new applications. This brings inspiration to the potential commercial and industrial uses of sesquiterpenes in Magnoliaceae.

Synthesis of novel Fe3O4@gly@Indole@CuNO3 magnetic nanoparticle as high-performance antibiotic absorbent, antimicrobial agent, and reusable magnetic Nano catalyst

The synthesis of nanoparticles has gained attention for their broad applications. Our research focused on developing a novel material, Fe3O4@gly@Indole (FGI), and exploring its diverse uses. FGI was synthesized in two steps using FeCl2.4H2O, FeCl3.6H2O, glycine, and indole-3-carboxaldehyde. Its structure was confirmed via FT-IR, XRD, VSM, SEM, TGA, and EDAX. Antimicrobial tests revealed FGI exhibited higher activity than some antibiotics, with a Minimum Inhibitory Concentration (MIC) of 1µg/mL against Staphylococcus aureus. To enhance its properties, a magnetic nanocatalyst (FGICu) was synthesized by combining FGI with Cu(NO3)2. FGICu proved effective in synthesizing chromeno[4,3-b]chromen-6-one derivatives, achieving 95% yield in 20minutes at 50°C. Additionally, FGICu outperformed FGI in antibacterial tests, showing a lower MIC of 0.5µg/mL and stronger bactericidal activity (MBC of 2-8µg/mL). FGICu also demonstrated significant potential as an adsorbent, with a maximum adsorption capacity of 500.8mg/g for tetracycline (TC). The adsorption mechanism involved electrostatic interactions, hydrogen bonding, and π-π stacking, with the SIPS model best fitting the isotherm and pseudo-second-order model describing the kinetics. FGICu maintained over 70% efficiency after five adsorption cycles, showing excellent stability and reusability. These findings suggest FGICu is a promising material for antimicrobial applications and pollutant removal from wastewater.

Multi-functional polysaccharides composite film containing cashew and jik leaf carbon dots: Properties and bioactivities

Carbon dots (CDs) from the leaf powders of cashew (C-CDs), jik (J-CDs) and the mixed cashew/jik (1:1) (CJ-CDs) using hydrothermal method were synthesized and characterized. All three CDs were incorporated into chitosan/starch composite (CS) film at the level of 3 % (w/w). Microstructure images revealed that all films had slight differences in surface and internal structure. Thickness of the CS film increased with the inclusion of fillers (CDs). Inclusion of CDs slightly reduced the tensile and water vapor barrier properties of the CS film. CS film containing C-CDs exhibited the improved elasticity, UV barrier and antioxidant activity among all the films tested. Color and opaqueness of the resulting films were governed by the yellowish CDs. Distinctive peaks of resulting CS film were detected in FTIR spectra, while all CDs had no marked effect on the spectra. The release of CDs from films was more pronounced in water than in alcoholic solutions (10–95 % ethanol). Strongest antibacterial activities against Listeria monocytogenes and Escherichia coli were recorded for CDs added film, in which the highest activities were found for CS/CJ-CDs film. Thermal stability was also enhanced in CS/CJ-CDs film. Thus, the CS film loaded with CDs, especially from the mixture of cashew and jik leaf powders could serve as a promising active packaging for inactivation of some pathogens in food products.

Antibacterial activity of cell-free supernatant produced by Lactobacillus coryniformis 7841 against Vibrio parahaemolyticus and its potential application in salmon preservation

In this study, a strain of lactic acid bacteria, whose cell-free supernatant (CFS) exhibited strong antibacterial activity against Vibrio parahaemolyticus, was isolated from traditional Chinese fermented vegetables and identified as Lactobacillus coryniformis 7841 (LC7841) based on morphological, biochemical, and molecular characteristics. The minimum bactericidal concentration and minimum inhibitory concentration of the 10-fold cell-free supernatant concentrate (CFSC) were both 10 μL/mL against V. parahaemolyticus. CFSC caused cell wall and membrane disruption of V. parahaemolyticus validated by the increasing leakages of intracellular substances (nucleic acids, proteins, and β-galactosidase), alkaline phosphatase and the accumulation of malondialdehyde. In further, scanning electron microscopy, transmission electron microscopy, and live-dead cell observation by confocal laser scanning microscope revealed that CFSC caused cell wall and membrane damages in V. parahaemolyticus in a concentration-dependent manner. The composite films incorporating CFSC in chitosan-gelatin based films were applied for salmon preservation. The composite films significantly inhibited the propagation of V. parahaemolyticus, decreased the decay rate, and prolonged the shelf-life of salmon. Consequently, these results indicated that CFC of LC7841 may have potential applications as biopreservatives against Vibrio-related contamination in seafood.

Cost-effective synthesis of zinc oxide/crab shell-derived chitosan nanocomposite: Insights into its biomedical applications.

For biomedical applications, material scientists all over the world are working to develop cost-effective technologies and thereby synthesize new nanocomposite materials that are biocompatible, bioactive, scalable and naturally abundant. This study focuses on synthesizing and evaluating nanocomposites of zinc oxide (ZnO) and chitosan (CS) derived from crab shells, in three different weight proportions (1:0.5, 1:1, and 1:2). ZnO/CS nanocomposites were synthesized using a soft-chemical method. Characterization of the nanocomposites was done using XRD, FESEM, EDAX, FTIR, and PL techniques. Among the three formulations, the ZnO/CS nanocomposite with a 1:2 ratio (ZnO/CS1:2) exhibited the most significant antioxidant, anti-diabetic, and antibacterial properties. The (ZnO/CS)1:2 demonstrated 89.46 and 90.85 % of inhibition in DPPH and superoxide free radical scavenging assays, respectively, and showed 91.86 % inhibition of alpha-glucosidase enzyme. It also exhibited strong antibacterial activity against both gram-positive (Staphylococcus epidermidis, Bacillus subtilis) and gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Additionally, the cytotoxicity of the (ZnO/CS)1:2 nanocomposite was assessed against the MCF-7 breast cancer cell line, showing an IC50 value of 11.58 ± 0.05 μg/mL at 30 μg/mL. The ZnO/CS (1:2) nanocomposite shows potential as a candidate for biomedical applications, particularly in antioxidant, anti-diabetic, antibacterial, and cytotoxicity activities.

Development and characterization of antibacterial marine extract-infused cellulose acetate nanofibers as wound dressings for combatting multidrug-resistant wound infections

Wound infections caused by multidrug-resistant bacteria pose a significant challenge globally in healthcare. Traditional wound dressings often lack efficacy against these resilient pathogens, necessitating the exploration of innovative approaches to combat infections and promote wound healing. This study was designed to investigate a novel wound dressing marine extract-infused electrospun cellulose acetate nanofibers (CANF) with particular emphasis on combating multidrug-resistant bacteria. Cellulose acetate (CA) solution was blended with marine extract (Heteroxenia Fuscescens soft coral, H. Fu) before the formation of electrospun nanofibers. The antibacterial activities of H. Fu extract and the prepared nanofiber mats were explored against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Staphylococcus epidermidis. Results displayed that H. Fu extract has a robust antibacterial action against tested bacteria. Different concentrations of H. Fu (0.05 g, 0.1 g, 0.2 g, and 0.3 g) were added to CA solutions, and named as H. Fu-1@CANF, H. Fu-2@CANF, H. Fu-3@CANF and H. Fu-4@CANF, respectively. The obtained results from SEM analysis demonstrated the smooth and uniform fibers. As observed, the results also domenstrated that the addition of H. Fu with specific concentrations (0.05 g, 0.1 g, 0.2 g) has no significant impact on the smooth properties of the formed nanofibers. Increasing the concentration of H. Fu (0.3 g) leads to the formation of nanofibers coated with huge beads. The contact angle values of CANF, H. Fu-1@CANF, H. Fu-2@CANF, and H. Fu-3@CANF were 33.3°, 57.1°, 60.8° and 62.9°, respectively. The prepared nanofiber samples were tested for their inhibitory impact on bacterial survival counts using the disc diffusion method. Important results from the study include the observation that H. Fu-3@CANF exhibited the largest zones of inhibition (ZOI) with diameters of 35 ± 0.25 mm for P. aeruginosa, 32 ± 0.65 mm for A. baumannii, 28 ± 0.14 mm for S. aureus, and 27.6 ± 0.48 mm for S. epidermidis. Additionally, the H. Fu-2@CANF sample demonstrated strong antibacterial activity, with ZOI diameters of 32 ± 0.56 mm, 29 ± 0.81 mm, 26 ± 0.27 mm, and 25.4 ± 0.28 mm for the respective bacteria. The Microtox® assay further evaluated the toxicity levels of the nanofiber mats, revealing that while all samples exhibited some toxicity, the H. Fu-3@CANF sample had the lowest toxicity profile. These findings highlight the potential of H. Fu-loaded nanofibers, particularly H. Fu-3@CANF, for broad-spectrum antibacterial applications. The study underscores the importance of incorporating bioactive compounds into nanofiber mats to enhance their antimicrobial properties, making them suitable candidates for medical and environmental applications requiring effective bacterial eradication.

A dissolving microneedle patch loaded with plumbagin/hydroxypropyl-β-cyclodextrin inclusion complex for infected wound healing

Treating infected wounds is facing a serious challenge due to the rapid spread of antibiotic resistance worldwide. In the search for novel antimicrobial drugs, natural products often serve as a crucial resource. Plumbagin (PLB) is the most important natural active ingredient in the root of Plumbago zeylanica L. known for its excellent antibacterial ability. However, the application of PLB is limited because of its poor water solubility, instability, and tendency to sublimate. In this study, we propose a solution by designing a hyaluronic acid (HA)/polyvinylpyrrolidone (PVP) dissolving microneedle patch loaded with PLB/hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex. PLB was encapsulated into the cavity of HP-β-CD to improve its solubility and stability using the neutralization agitation method. The formation of the inclusion complex significantly increased the water solubility of PLB to 1350 ± 6.8 μg/mL, which is 17 times higher than its original value of 79.3 ± 1.7 μg/mL. The encapsulation efficiency was found to be 94.82 ± 3.34%. In vitro drug release studies, PLB microneedles loaded with PLB/HP-β-CD inclusion complex rapidly released into PBS within 15min. Furthermore, the PLB microneedles exhibited strong antibacterial activity against Staphylococcus aureus (S. aureus) both in vivo and in vitro. They also remarkably accelerated the healing of infected wounds in mice by enhancing collagen deposition and re-epithelialization, reducing inflammation, and stimulating angiogenesis. Overall, this multifunctional microneedle patch shows promising potential for clinical applications in the healing of infected wounds.