Papers by Keyword: Antimicrobial

Abstract: In contrast to bulk materials, nanoparticles, which are distinguished by their extremely small size and remarkable surface area-to-volume ratio, have unique physical and chemical properties. Among the several metal-oxide nanoparticles, green zinc oxide nanoparticles have drawn a lot of interest because of their wide range of uses, including antibacterial, antifungal, antimicrobial, and anticancer activities. To assess the potential of zinc oxide nanoparticles in developing domains like bioapplications, this thorough investigation offers insights into the shape and structure of ZnO NPs as well as their characteristics and attributes using characterisation procedures. This work is novel because it carefully examines various synthesis techniques for zinc oxide nanoparticles, provides a thorough understanding of their chemical and biological complexities, and investigates how these nanoparticles' special properties can revolutionise this field. Through this investigation, we want to clarify the complexities of synthesis while also illuminating the wide range of uses and constraints of zinc oxide nanoparticles, offering a path forward for further nanotechnology research and development.

Abstract: This study investigated the incorporation of lignin nanoparticles derived from black liquor (S-BLNAce) into polybutylene succinate (PBS) to enhance the antimicrobial and irradiation-shielding properties of PBS composite films for packaging applications. Black liquor, a by-product of paper industry, was utilized to produce nanolignin through acetone fractionation and anti-solvent precipitation techniques. PBS composite films with varying S-BLNAce concentrations (0.5–2.0%wt) were fabricated via blow-molding and evaluated for mechanical, irradiation-shielding, and antimicrobial properties. The addition of S-BLNAce nanolignin improved the tensile strength and modulus of PBS, particularly at lower concentrations, while slightly reducing elongation at break. Films with higher nanolignin content exhibited enhanced irradiation shielding, especially in the UV-A and UV-B regions, and demonstrated significant antibacterial activity against Escherichia coli and Staphylococcus aureus. These findings highlight the potential of nanolignin as a bio-based additive for developing high-performance, sustainable packaging materials, aligning with circular economy and sustainability goals.

Abstract: Polyvinyl alcohol (PVA) is a non-toxic, thermoplastic polymer that is completely biodegradable. So it is based on many composite materials for biomedical applications. In this study, various specimens were prepared by solvent casting method and then tested by tensile, FTIR, contact angle, SEM, antibacterial and cytotoxicity test. The results obtained showed the tensile strength decreased with the addition of PEG and then tended to improve after the addition of collagen and nano-titanium oxide. The wettability test shows the prepared specimens changed from hydrophobic to hydrophilic properties. The biological properties explained that the prepared composite had a better antibacterial effect and none of the samples had a toxic effect.

Abstract: A study to find the effectiveness of chitosan concentration as a natural preservative on Kenyan fish (Sarda orientalis) has been conducted. The chitosan powder used is extracted from tiger prawn (Penaeus monodon) shells, and it is used in the form of a solution with a concentration of 1%, 1.5%, 2%, and 2.5%. Fresh kenyar fish of 500 g were soaked in those chitosan solutions and named A1, A2, A3, and A4, respectively. Two sample groups were prepared as a comparison; they weren’t treated with any chitosan solution; they were A02, 500 g of kenyar fish soaked in 2% acetic acid, and A01, 500 g of kenyar fish without any treatment. The soaking times were varied as 20, 40, and 60 minutes. Storage is carried out at room temperature. The activity of chitosan as a fish preservative was analyzed using various methods, including pH, organoleptic, and antimicrobial tests. The measurements of pH and organoleptic test were made at 0, 24, 48, and 72 hours. The antimicrobial tests were carried out after 24 hours of storage. The study concluded that the effective concentration of chitosan as a preservative agent of fresh kenyar fish is 2.5% (A4) with 40 minutes of soaking time, with the quality parameters are pH 5, an organoleptic score of 9, and the total number of microbes is 1.2 x 10⁵ CFU/g.

Abstract: Black galingale is a medicinal plant that has medicinal properties. The major constituents found in black galingale rhizomes are flavonoids, which display antioxidant activities. Therefore, in this research, the focus is to isolate and structurally determine bioactive compounds from the ethyl acetate extract of black galingale rhizomes and evaluate their antioxidant and antimicrobial activity, The black galingale rhizomes were extracted by maceration using ethyl acetate as a solvent. the compounds were isolated by column chromatography using hexane: ethyl acetate as an eluent solvent system. The isolated compounds were examined and characterized using FT-IR, UV-Vis, and NMR techniques, examined antioxidant activity by DPPH assay, and antimicrobial activity. From the extraction of ethyl acetate extract, it was found that 4 pure flavonoid compounds could be extracted. The FT-IR spectral data of 4 compounds showed a unique vibration corresponding to OH stretching, CH stretching, C=O stretching, C=C stretching of an aromatic ring, and C-O-C bond. Antioxidant activity testing by DPPH assay found 5-hydroxy-3,7-dimethoxyflavone (1) to have the highest antioxidant activity at 73.79% compared to the standard Trolox with 133.37±1.60 mM. Antimicrobial activity testing found that 3,5,7-trimethoxyflavone (3) showed the best growth inhibition activities against B. megaterium and S. aureus, Moreover, it studies the nanoemulsion properties of 5-hydroxy-3,7-dimethoxyflavone (1) was found stable with a nanoparticle size of 21.1 nm, a zeta potential of-49.7 mV, and has PDI of 0.227. Therefore, this research shows that the extract from black galingale rhizome could be used as an active ingredient in the cosmetics industry.

Abstract: The development of bioplastics is currently increasing, because bioplastics are an effort to reduce landfill waste. One of the bioplastics that has good degradation ability is cornstarch. The addition of nanoparticles was carried out to improve the properties of bioplastic packaging. One example of the application of nanotechnology in food packaging is silver nanoparticles (AgNP), known as antimicrobial substances. This research was conducted to determine the effect of adding AgNP (0%, 1%, and 2%) on the antimicrobial and biodegradation of cornstarch bioplastics. Bioplastics are made by casting method. AgNP was used from the synthesis of silver nitrate (AgNO₃) and trisodium citrate dihydrate (C₆H₅Na₃O₇.2H₂O) as a reducing agent and stabilizer by chemical reduction method, which was then analyzed by FTIR. The results obtained showed that cornstarch bioplastic AgNP 1% has the ability to estimate the fastest degradation time among other concentrations with an addition of 103 days. Cornstarch bioplastic AgNP 2% had the best ability to inhibit bacterial growth, with antibacterial inhibition zone diameters of 11.03 mm (Staphylococcus aureus) and 10.61 mm (Escherichia coli). However, AgNP could not inhibit the mold growth of Aspergillus niger. The addition of AgNP to cornstarch bioplastics can increase the degradation capabilities and antibacterial activity of bioplastics.

Abstract: Polymer-based hydrogels are suitable for development as wound dressings because the hydrogel can regulate the amount of fluid and moisture in the wound area, exhibit a network structure, and be compatible with the human body. Therefore, this work focused on the preparation of 2% w/v (Chitosan:CS)/2%,4%,6% w/v (Poly(vinyl alcohol):PVA) gel containing silver nanoparticles for antibacterial use, synthesized by the chemical crosslinking method with glutaraldehyde. Silver nanoparticles were prepared at a concentration of 1 mmol with black lemon extract as a reducing agent and a stabilizer packaged in the gel. From the study of absorbance, particle size, and morphology, it was found that silver nanoparticles were 10.60± 2.20 nm, with good dispersion and spherical shape. The swelling behavior of 2% w/v CS/2% w/v PVA gel showed the highest swelling at 95.74±21.29%. In addition, 2% w/v CS/2% w/v PVA gel containing silver nanoparticles could inhibit the growth of gram-positive and gram-negative bacterial microorganisms. Thus 2% w/v CS/2% w/v PVA gel containing silver nanoparticles is suitable for medical applications.

Abstract: Healthcare-associated infections (HAIs) are a major safety concern globally that contribute to mortality rates amongst patients especially associated with indwelling or implanted medical devices. The advanced metal-oxide nanocomposites (MNPs) embedded in polymer matrix present an outstanding antibacterial profile, especially for MDR strains owing to reactive oxygen species (ROS) and free radicals’ mode of action. To date, there is still a lack of knowledge on the implication of external reactive species from MNPs-based polymers to humans. This study investigates the bio-interaction of TiO2-ZnO nanocomposite films embedded in linear low-density polyethylene (LLDPE/ TiO2-ZnO) on human fibroblast and blood cell lines model at molecular genes and protein level. The initial analysis of the in vitro bio-interaction responses on fibroblast and blood cell line models showed signs of cell membrane integrity disturbance, which might be due to free radicals’ activities, such as the release of intracellular ROS and Zn ions (Zn²⁺) during the initial cellular adaptation process on the TiO2–ZnO polymer nanocomposite film. Further findings found that cell–polymer nanocomposite film interaction could possibly trigger transitory oxidative stress response and cellular redox regulation via NF-kβ interactions. However, further comprehensive studies are needed to support this study, especially involving animal models.

Abstract: The hydrocolloid impression material is one of the most important materials extensively used in several procedures in the dental field. It is mainly applied for diagnostic and planning in the rehabilitation of oral, orthodontic, and maxillofacial prostheses due to its biocompatibility with the oral tissues, low toxicity, ease of use, and relatively low cost. When doing the impression, the material might be contaminated with blood, saliva, and biofilm from within the patient’s mouth. In these procedures, there are high chance that the microorganisms can be transmitted from patients to the casting materials and then to the dentists or to the dental lab technicians. Several types of disinfectants have been introduced for use to disinfect dental impressions. This study aims to investigate the antimicrobial potential of vanillin-incorporated irreversible hydrocolloid impression material on Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans. The hydrocolloid impression material used in this study is Alginate, Kromopan class A type I, Lascod, Italy. Different concentrations of vanillin (0.1%, 0.5%, and 1% w/w) were added to the impression powder, and the impression samples were made by mixing the alginate powder with water and pouring them on sterile plastic plates. Staphylococcus aureus ATCC 5638, Klebsiella pneumoniae (clinical isolate), Escherichia coli ATCC 11775, and Candida albicans ATCC 10231 were prepared to 10⁵ CFU/ml suspensions in sterile normal saline solution. A total of 100 μL of each microbial suspension was evenly spread onto the surface of the impression and left for 1 min. Then, a 2 x 2 cm² sterile Whatman filter paper was placed on the impression sample surface to make an imprint and transferred to the Brain Heart Infusion (BHI) agar plate. The number of colonies growing on the BHI agar was counted after incubation at 37°C for 24-48 h. Impression material without vanillin was used as a control. It was found that adding vanillin to the materials could significantly inhibit all tested microorganisms, and the inhibitory efficiency ranged from 12% to 98%. K. pneumoniae showed the most resistance since the inhibitory effect started at 0.5% w/w vanillin and the maximum suppression was 84% at 1% w/w vanillin. On the other hand, S. aureus appeared to be the most sensitive species, as the suppressive response started at 0.1% w/w vanillin and the percentage of inhibition was as high as 98% at 1% w/w vanillin. In conclusion, we combined different concentrations of vanillin (0.1%, 0.5%, and 1% w/w) into the impression material and it showed a significant antimicrobial potential against all tested oral bacteria and yeasts (S. aureus, K. pneumoniae, E. coli, and C. albicans). The suppressive effects were dose-dependent and ranged from 12% to 98%. This did not only disinfect the impression material from the inside but also disinfected the impression from the time it was inserted into the patient’s mouth. Using this hydrocolloid impression material incorporated with vanillin could be beneficial to eliminate cross-infection for dental personnel. Nonetheless, further studies are necessary to investigate some physical properties of this impression material, such as setting time, tensile strength, elastic recovery, and detailed reproduction.

Abstract: In this study, sheet-like MnO₂/ZnO microflower (MnO₂/ZnO) loaded on cotton fabric was prepared via a facile reflux-thermal deposition combined technique. The coated fabric and as-fabricated particles were analyzed through numerous characterization techniques including field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), tensile strength, Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) as well as photoluminescence (PL) measurements. The optical trait of the ZnO was significantly improved by the addition of MnO₂ that extended reflectance edges in the visible light region. The treated cotton fabric greatly inhibited the growth of Escherichia Coli bacteria and Aspergillus Niger fungi as testified by the zone of inhibition surrounding the fabric samples. The self-cleaning outcomes also demonstrated that 3% MnO₂/ZnO/fabric presented highest visible light photodegradation of phenol among the samples. The promising performance of the cotton fabric coated by MnO₂/ZnO composite was related to the reactive oxygen species produced by the heterojunction photocatalytic mechanism under exposure of visible light.