scholarly journals The Effects of Copper Addition on The Structure and Antibacterial Properties of Biomedical Glasses

2020 ◽  
Author(s):  
Leyla Mojtabavi ◽  
Amir Razavi

AbstractIn this work, we studied the effects of copper incorporation in the composition of bioactive glass. Three different glass compositions were synthesized with 0, 3, and 6 mol% of copper addition. X-Ray Diffraction (XRD) patterns confirmed that an amorphous microstructure was obtained for all three glass compositions. Results from Differential Thermal Analysis (DTA) showed that the copper addition in the glass lowers the glass transition temperature, from 646°C to 590°C when added at 6 mol%. X-ray Photoelectron (XPS) survey and high-resolution scans were performed to study the structural effects of copper addition in the glass. Results indicated that the incorporation of copper changes the ratio of bridging to non-birding oxygens in the structure. Glasses were further analyzed for their structure with Nuclear Magnetic Resonance (NMR) spectroscopy, which indicated that copper acts as a network modifier in the glass composition and copper-containing glasses show a less connected microstructure. Antibacterial efficacy of the glasses was analyzed against E. coli and S. epidermis. Copper-containing glasses showed a significantly higher inhibition zone compared to control glass. The glass with 6 mol% copper, exhibited inhibition zones of 9 and 16mm against E. coli and S. epidermis bacteria, respectively.

2021 ◽  
Vol 18 (4) ◽  
pp. 119-123
Author(s):  
Doaa Kaduim ◽  
Zaid Mahmoud ◽  
Falah Mousa

The biosynthesis of iron oxide (Fe2O3, also known as haematite) nano particles (NPs) using Hydra helix and Beta vulgaris aqueous extracts were adduced, respectively, where the extracts act as a stabiliser and reductant reagent. The crystal structure and size of particles were investigated using X-ray diffraction (XRD), while the morphology was examined using field emission scanning electron microscopy (FESEM), XRD patterns showed the synthesised nanoparticles with well-crystallised structure from Beta vulgaris extract with size 12 nm, while the results by using Hydra helix showed many peaks back to Goethite phase with 16 nm. The antibacterial and antifungal activity were examined using Staphylococcus (showed inhibition zone diameter 23 mm, 16 mm using Hydra helix and Beta vulgaris, respectively), E. coli (showed no inhibition) and Candida fungi (showed inhibition zone 16 mm, 11 mm using Hydra helix and Beta vulgaris, respectively).


2020 ◽  
Vol 12 (4) ◽  
pp. 542-547
Author(s):  
Shikha Sharma ◽  
Fehmeeda Khatoon

An environmental technique of herbal mediated blend of Ag nanoparticles is a substantial stage in the ground of nanotechnology. Chitosan (CS) is a polymer which is biocompatible and antibacterial. In this work, we have synthesized CS–Ag Nano hydrogel which is form with chitosan-based hydrogel merged in the herbal synthesized Ag nanoparticles. These green synthesized Ag-nanoparticles made from Polygonum bistorta plant leaves and described with the assistance of UV-vis spectrophotometer, and Dynamic Light Scattering (DLS). In this work our main focus to synthesized CS–Ag Nano hydrogel. These hydrogel was described by Fourier transform infrared (FTIR) spectroscopic method, X-ray diffraction (XRD) method, and contact angle. Nanoparticle size distribution was within 1 to 100 nm by DLS and the optimum wavelength was noted in 400 to 450 nm by UV-vis spectroscopic readings. A good antibacterial behavior has been displayed by these synthesized CS–Ag Nano hydrogel films against both E. coli (gram –ve) and S. aureus (gram +ve) with the maximum 7 mm inhibition zone.


2014 ◽  
Vol 979 ◽  
pp. 327-330
Author(s):  
W. Siriprom ◽  
K. Teanchai

The aim of this work investigated the antibacterial properties of oxide compound from agricultural waste material. The oxide compounds were prepared by annealed the agricultural waste material upon consequence of temperature. After that, the crystalline structure, morphology, chemical composition and estimation of oxide compound were conducted by X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) and Fourier Transform Infrared Spectroscopy (FTIR). It was observed that the XRD patterns demonstrated the lime phase and cristobalite phase after heat treatment. Another that, the result from EDXRF and FTIR was in good agreement with the result of XRD. For anti-bacterial efficacy were utilized the lime phase and cristobalite phase for testing antibacterial activities which the agar diffusion technique. It was found that the inhibition zones were clearly visible for both agents, found to exhibit antibacterial action against Escherichia coli.


2016 ◽  
Vol 73 (8) ◽  
pp. 1910-1919 ◽  
Author(s):  
Zhong-Hua Huang ◽  
Yan-Na Yin ◽  
Gu-li-mi-la Aikebaier ◽  
Yan Zhang

A novel positively charged N-[(2-hydroxy-3-trimethylammonium)propyl] chloride chitosan (HTCC)-Ag/polyethersulfone (PES) composite nanofiltration membrane was easily prepared by coating the active layer, HTCC, onto PES as the support through epichlorohydrin as the cross-linking reagent and nano-Ag particles as the introduced inorganic components. Scanning election microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray diffraction were employed to characterize the morphology of the resultant membranes, of which the molecular weight cut-off was about 941 Da. At 25 °C, the pure water permeability is 16.27 L/h·m2·MPa. Our results showed that the rejection of pharmaceuticals and personal care products (PPCPs) followed the sequence: atenolol > carbamazepine > ibuprofen, confirming that the membranes were positively charged. The antibacterial properties of the membranes were compared to elucidate the existence of Ag nanoparticles which help to improve antibacterial activity against Gram-negative Escherichia coli (DH5α, Rosetta) and Gram-positive Bacillus subtilis. The inhibition zone diameters of HTCC-Ag/PES membranes towards E. coli DH5α, E. coli Rosetta and Bacillus subtilis were 17.77, 16.18, and 15.44 mm, respectively. It was found that HTCC-Ag/PES membrane has a better antibacterial activity against E. coli than against Bacillus subtilis, especially for E. coli DH5α.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 43
Author(s):  
Kun-Yauh Shih ◽  
Shiou-Ching Yu

Nanomaterials with high antibacterial activity and low cytotoxicity have attracted extensive attention from scientists. In this study, europium (III) hydroxide (Eu(OH)3)/reduced graphene oxide (RGO) nanocomposites were synthesized using a rapid, one-step method, and their antibacterial activity against Escherichia coli (E. coli) was investigated using the synergistic effect of the antibacterial activity between Eu and graphene oxide (GO). The Eu(OH)3/RGO nanocomposites were prepared using a microwave-assisted synthesis method and characterized using X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, Raman spectroscopy, and Fourier-transform infrared spectroscopy. Raman sprectroscopy and X-ray diffraction confirmed the pure hexagonal phase structure of the nanocomposites. Further, the antibacterial properties of Eu(OH)3/RGO were investigated using the minimum inhibitory concentration assay, colony counting method, inhibition zone diameter, and optical density measurements. The results revealed that the Eu(OH)3/RGO exhibited a superior inhibition effect against E. coli and a larger inhibition zone diameter compared to RGO and Eu(OH)3. Further, the reusability test revealed that Eu(OH)3/RGO nanocomposite retained above 98% of its bacterial inhibition effect after seven consecutive applications. The high antibacterial activity of the Eu(OH)3/RGO nanocomposite could be attributed to the release of Eu3+ ions from the nanocomposite and the sharp edge of RGO. These results indicated the potential bactericidal applications of the Eu(OH)3/RGO nanocomposite.


2013 ◽  
Vol 744 ◽  
pp. 311-314
Author(s):  
Chun Ping Wang ◽  
Shao Ping Chen ◽  
Jia Chao Chen

In order to optimize the preparation process of silver-loaded diatomite, the effect of the adsorption time, temperature and the concentration of silver nitrate on the content of silver ions in diatomite were investigated through ion exchange experiment method. And the antibacterial properties were measured by Haloes method. The samples were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results show that the loading of the silver ions is no change in the microscopic structure of the diatomite, the silver exists in diatomite as the ion. The content of silver in the diatomite is 0.523g/g under the condition of AgNO3 (0.5mol/L) and temperature 70°C. The silver-loaded diatomite has good antibacterial activity on E. coli.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 507
Author(s):  
Xionggang Wang ◽  
Lingna Cui ◽  
Shuhong Fan ◽  
Xia Li ◽  
Yuejun Liu

Antibacterial packaging materials can reduce the microbial contamination of food surfaces. In this study, magnesium oxide (MgO) nanoparticles were synthesized and then coated with cetrimonium bromide (CTAB). CTAB-modified MgO (MgO@CTAB) was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis. Then, different loadings of MgO@CTAB were mixed with poly(butylene adipate-co-terephthalate) (PBAT) by melt compounding. The results showed that the addition of MgO@CTAB deteriorated the thermal stability of PBAT due to MgO serving as a catalyst to promote the thermal degradation of PBAT. In addition, MgO@CTAB could serve as a nucleating agent to improve the crystallinity of PBAT. With the optimal 3 wt% of MgO@CTAB, the tensile strength of PBAT/MgO@CTAB increased from 26.66 to 29.90 MPa, with a slight enhancement in elongation at break. SEM observations and dynamical rheological measurements revealed that aggregation occurred when the content of MgO@CTAB exceeded 5 wt%. The presence of MgO@CTAB endowed PBAT with antibacterial properties. The bacterial inhibition zone increased with the increasing content of MgO@CTAB. In addition, MgO@CTAB had a better antibacterial efficiency against Gram-positive bacterial S. aureus than Gram-negative bacterial E. coli.


Author(s):  
James A. Lake

The understanding of ribosome structure has advanced considerably in the last several years. Biochemists have characterized the constituent proteins and rRNA's of ribosomes. Complete sequences have been determined for some ribosomal proteins and specific antibodies have been prepared against all E. coli small subunit proteins. In addition, a number of naturally occuring systems of three dimensional ribosome crystals which are suitable for structural studies have been observed in eukaryotes. Although the crystals are, in general, too small for X-ray diffraction, their size is ideal for electron microscopy.


Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.


Sign in / Sign up

Export Citation Format

Share Document