Antibacterial Activities Of Samples Research Articles

Synthesis and characterization of Ag-ion-exchanged zeolite/TiO2 nanocomposites for antibacterial applications and photocatalytic degradation of antibiotics

This paper investigates the synthesis, antibacterial, and photocatalytic properties of silver ion-exchanged natural zeolite/TiO2 photocatalyst nanocomposite. Zeolite is known to have a porous surface structure, making it an ideal substrate and framework in different nanocomposites. Moreover, natural zeolite has a superior thermal and chemical stability, with hardly any reactivity with chemicals. Finding an effective and low-cost method to remove both antibiotics and bacteria from water resources has become a vital global issue due to the worldwide excessive use of chemicals and antibiotics. This research aims to propose a facile method to synthesize Ag-ion-exchanged zeolite/TiO2 catalyst for anti-bacterial purposes and photocatalytic removal of atibiotics from wastewaters. TiO2 particles were deposited on the surface of natural zeolite. Ag ion exchanging was performed via a liquid ion-exchange method using 0.1 M AgNO3 solution. X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR) were used to evaluate the structure of synthesized powders. Antibacterial activities of samples were assessed, using Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 by disc diffusion method. It was shown that Ag-containing nanocomposite samples have an improved antibacterial performance in both cases. Results showed that the synthesized catalyst has promising potentials in wastewater treatment.

Surface modification of TiO2 nanoparticles with CuO for visible-light antibacterial applications and photocatalytic degradation of antibiotics

This paper investigates the synthesis and characterization of photoactive TiO2/CuO nanocomposites for the simultaneous antibacterial applications and photocatalytic removal of Amoxicilline from wastewaters. Effective removal of biological and organic contaminants from water resources has become a global challenge due to contaminants' complexity and extensive use. TiO2/CuO heterojunctions with different CuO loadings were synthesized using a straightforward precipitation method. Electron microscopy, energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), ultraviolet–visible (UV-VIS) analyses were used to characterize synthesized samples. Antibacterial activities of samples were investigated against Staphylococcus aureus. Also, the applicability of synthesized powders in the photocatalytic removal of Amoxicilline from wastewater was methodically investigated. Results showed that the photocatalytic activity of synthesized TiO2/CuO nanocomposites is highly dependent on the CuO loadings of samples. CuO loading can also increase the light absorption within the visible light region, making TiO2/CuO samples applicable in the visible light region. Results also showed that CuO loading greatly enhances the antibacterial characteristics of samples.

Fabrication and evaluation of chitosan/gelatin/PVA hydrogel incorporating honey for wound healing applications: An in vitro, in vivo study

In this study, physically cross-linked hydrogels were developed by freezing-thawing method while different concentrations of honey were included into the hydrogels for accelerated wound healing. The hydrogel was composed of chitosan, polyvinyl alcohol (PVA), and gelatin with the ratio of 2:1:1 (v/v), respectively. Further, the effect of honey concentrations on antibacterial properties, and cell behavior was investigated. In vivo studies, including wound healing mechanism using rat model and histological analysis of section tissue samples were performed. The results illustrated that the incorporation of honey in hydrogels increased the ultimate strain of hydrogels approximately two times, while reduced the ultimate tensile strength and elastic modulus of hydrogels. Moreover, the antibacterial activities of samples were increased by increasing the concentration of honey. Regarding MTT assay, as the concentration of honey increased, the cell viability of hydrogels was enhanced until an optimal amount of honey. Further, the integration of honey into the hydrogel matrix results in the maintenance of a well-structured layer of epidermis containing mature collagen and accelerates the rate of wound healing. The 3D Chitosan/PVA/Gelatin hydrogel containing honey with appropriate mechanical, antibacterial activity, and biocompatibility could be a promising approach for wound healing.

New stabilizer Cellulose Nano Rods-Zinc Oxide (CNR-ZnO) material for nanocomposite synthesis and anti-bacterial applications

Zinc oxide (ZnO) nanorods were fabricated using Cellulose Nano Rods (CNR) as a new stabilizer material. Synthesized of ZnO-CNR nanocomposites, with a molar ratio of ZnO to CNR (1/2g) were prepared in distilled water. The nanocomposites were distinguished using X-ray diffraction (XRD), ultraviolet-visible (UV-Vis), and Field Emission scanning electron microscope (FESEM) techniques. XRD data were showed, the ZnO nanorods with a hexagonal wurtzite structure such readily scattered inside CNR with an average size 20-40 nm. (FESEM) images showed the homogenous morphology of Zinc oxide rods. The optimum ratio of ZnO-CNR was selected to be the tiny size of the ZnO nanorods that yielded a good stabilizer material and antibacterial activity. The ultraviolet-visible (UV-Vis) absorption spectrum of the ZnO-CNR nanocomposites appeared absorption peaks in the ultraviolet region at (350-360 nm) wavelength attributes with the energy gap of (3.41 eV) of ZnO-CNR. The antibacterial activities of samples have been investigated against the Gram-positive (pneumonia) and gram-negative (pseudomonas). The maximum antibacterial activities against the Gram-positive (pneumonia) of ZnO nanorods and of ZnO- cellulose nanorods are 16 mm and 22 mm respectively. The optimum anti-bacterial activities versus the Gram-negative (pseudomonas) of zinc oxide nanorods and zinc oxide- cellulose nanorods are 17 mm and 19 mm respectively. The optimum anti-bacterial activities versus the Gram-negative (pseudomonas) of zinc oxide nanosheet and of zinc oxide- cellulose nanorods are 17 mm and 22 mm.

Preparation and Characterization for Antibacterial Activities of 3D Printing Polyetheretherketone Disks Coated with Various Ratios of Ampicillin and Vancomycin Salts

In this study, polyetheretherketone (PEEK) materials coated with various ratios of two kinds of antibiotic agents (ampicillin and/or vancomycin salts) were prepared. A modified 3D printer based on fused deposition modeling was employed to prepare PEEK disks. Coating ampicillin and/or vancomycin salts onto the PEEK disks was carried out using the biodegradable poly (lactic-co-glycolic acid) (PLGA) polymer as a binder and a control unit for the drug release in the buffer solution. The effects of various rations of ampicillin and/or vancomycin salts in the PLGA polymer on the PEEK substrates, the release profiles of various drugs, and antibacterial activities of the samples were investigated. Temperature of the heated nozzle in a commerical 3D printer was set at 340 °C. After systemic investigations of the qualities of PEEK disks, a diameter of the heated nozzle of 0.6 mm in the 3D printer was employed for the preparation of PEEK disks. Results of drug release profiles from samples into buffer solution show that the antibacterial activities of samples can continue up to 28 days. In the inhibition zone test of samples, the release amounts of antibiotic agents from the PEEK samples can inhibit S. aureus with activity of over 40% in 30 days tests and most of them can have inhibition activities of higher than 60% during the test. These results showed that a simple and low-cost 3D printing method for the preparation of PEEK/antibiotic agents/PLGA samples can have further applications in biomedical-related technology.

Effect of Silver Ions on the Structural and Antibacterial Properties of Bone Replacement Material

Antibacterial materials based on calcium phosphates have wide range of biomedical applications in the prevention of microbial infections. The synthesis of inorganic mineral component of bone i.e. hydroxyapatite was done with the addition of silver (Ag) (5-15 wt %) as antibacterial agent. The wet precipitation synthesis was carried out using diammonium hydrogen phosphate and calcium nitrate as P and Ca precursors. The presence and effect of silver addition on the structure was studied using Fourier Transform-Infrared (FTIR) spectroscopy and Energy Dispersive X-ray (EDX) techniques. The antibacterial properties of all samples were evaluated using Disc Diffusion Technique (DDT) againstS. aureus,B. subtilis, P. aeruginosaandE. coli. Antibacterial activities of samples were found to vary depending on the bacterial species and Ag loading percentage. The antibacterial assay suggested that the addition of Ag ions within hydroxyapatite can be effectively provided the required level of antibacterial activity against bacteria.

Synthesis, Antibacterial and Thermal Studies of Cellulose Nanocrystal Stabilized ZnO-Ag Heterostructure Nanoparticles

Synthesis of ZnO-Ag heterostructure nanoparticles was carried out by a precipitation method with cellulose nanocrystals (CNCs) as a stabilizer for antimicrobial and thermal studies. ZnO-Ag nanoparticles were obtained from various weight percentages of added AgNO3 relative to Zn precursors for evaluating the best composition with enhanced functional properties. The ZnO-Ag/CNCs samples were characterized systematically by TEM, XRD, UV, TGA and DTG. From the TEM studies we observed that ZnO-Ag heterostructure nanoparticles have spherical shapes with size diameters in a 9–35 nm range. The antibacterial activities of samples were assessed against the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The CNCs-stabilized ZnO-Ag exhibited greater bactericidal activity compared to cellulose-free ZnO-Ag heterostructure nanoparticles of the same particle size. The incorporation of ZnO-Ag hetreostructure nanoparticles significantly increased the thermal stability of cellulose nanocrystals.

The impact of nitrogen low temperature plasma treatment upon the physical–chemical properties of polyester fabric

Thermal properties, light reflection, dye absorption, and resistance against bacteria growth have made fibers and textiles very important and applicable in industry. These are mainly attributed to the structure and the surface characteristics, and their modification appears to be very contribute to improving the properties of textiles. Most of the methods aimed at such modifications are implemented in a liquid phase. However, cold plasma has some primacy; it can be done in dry areas, does not have any environmental harm or pollution, and reduces the required energy. In this study, polyester was used and its surface properties were investigated under plasma treatment in nitrogen gas for 2 min irradiation with 1 and 2 keV ions with intensities of 0.04, 0.05, 0.06, 0.08, and 0.1 mA. Changes in properties such as dyeability, thermal, and antibacterial activities of samples were investigated after plasma treatment. The results reveal that cold plasma treatment on polyester under nitrogen gas for 2 min has many suitable effects such as more disperse and acidic dye absorption, improvement of crystalline regions, and antibacterial activity in fabric. Besides, Fourier transform infrared shows that plasma treatment does not have any impact on the bulk properties of polyester fabric.