scholarly journals Investigation of the Antibacterial Properties of Silver-Doped Amorphous Carbon Coatings Produced by Low Pressure Magnetron Assisted Acetylene Discharges

2022 ◽  
Vol 23 (1) ◽  
pp. 563
Author(s):  
Valentin Job ◽  
Julie Laloy ◽  
Vincent Maloteau ◽  
Emile Haye ◽  
Stéphane Lucas ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Amorphous Carbon ◽  
Antibacterial Properties ◽  
Carbon Matrix ◽  
Modes Of Transmission ◽  
Gram Positive Bacteria ◽  
Multiple Exposures ◽  
Environmental Surfaces ◽  
Hospital Acquired ◽  
Amorphous Carbon Coatings

Hospital-acquired infections are responsible for a significant part of morbidity and mortality. Among the possible modes of transmission, this study focuses on environmental surfaces by developing innovative antibacterial coatings that can be applied on interior fittings in hospitals. This work aims to optimize a coating made of an amorphous carbon matrix doped with silver (a-C:H:Ag) produced by a hybrid PVD/PECVD process and to evaluate its antibacterial activity. We present a coating characterization (chemical composition and morphology) as well as its stability in an ageing process and after multiple exposures to bacteria. The antibacterial activity of the coatings is demonstrated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria through several bioassays. Moreover, the data suggest a crucial role of silver diffusion towards the surface and nanoparticle formation to explain the very promising anti-bacterial activities reported in this work.

Preparation of bioactive and antibacterial PMMA-based bone cement by modification with quaternary ammonium and alkoxysilane

2021 ◽  
pp. 088532822110044
Author(s):  
Haiyang Wang ◽  
Toshinari Maeda ◽  
Toshiki Miyazaki
Keyword(s):  
Antibacterial Activity ◽  
Methyl Methacrylate ◽  
Bone Cement ◽  
Setting Time ◽  
Antibacterial Properties ◽  
The Body ◽  
Apatite Formation ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria

Bone cement based on poly(methyl methacrylate) (PMMA) powder and methyl methacrylate (MMA) liquid is a very popular biomaterial used for the fixation of artificial joints. However, there is a risk of this cement loosening from bone because of a lack of bone-bonding bioactivity. Apatite formation in the body environment is a prerequisite for cement bioactivity. Additionally, suppression of infection during implantation is required for bone cements to be successfully introduced into the human body. In this study, we modified PMMA cement with γ-methacryloxypropyltrimetoxysilane and calcium acetate to introduce bioactive properties and 2-( tert-butylamino)ethyl methacrylate (TBAEMA) to provide antibacterial properties. The long-term antibacterial activity is attributed to the copolymerization of TBAEMA and MMA. As the TBAEMA content increased, the setting time increased and the compressive strength decreased. After soaking in simulated body fluid, an apatite layer was detected within 7 days, irrespective of the TBAEMA content. The cement showed better antibacterial activity against Gram-negative E. Coli than Gram-positive bacteria; however, of the Gram-positive bacteria investigated, B. subtilis was more susceptible than S. aureus.

scholarly journals NOVEL COMPOSITE OF SILVER-BACTERIAL CELLULOSE (Ag-BC) FROM SIWALAN SAP (Borassus flabellifer) AND ITS ANTIBACTERIAL ACTIVITY

2020 ◽  
Vol 83 (1) ◽  
pp. 19-25
Author(s):  
Suntini Suntini ◽  
Anastasia Wheni Indrianingsih ◽  
Harjono Harjono
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Cellulose ◽  
Antibacterial Properties ◽  
Reduction Process ◽  
Diffusion Method ◽  
Natural Material ◽  
Gram Positive Bacteria ◽  
Antibacterial Assay ◽  
Natural Composite

Recently, a wound healing from natural composite with excellent properties is in a high demand. In this study, a novel composite of bacterial cellulose made from Siwalan sap (Borassus flabellifer) was achieved. Siwalan is a common plant in Java Island of Indonesia and the application is very limited for beverage only. This study aims to determine the effect of the AgNO3/NaBH4 concentration ratio in the development of Ag-BC composites and its antibacterial properties from Siwalan sap. Ag-BC composites were prepared by impregnating the silver solution into the BC matrix through the reduction process with NaBH4. Characterization of Ag-BC composites conducted using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX). Antibacterial assay was performed using disc diffusion method against Salmonella typhimurium (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. The characterization of Ag-BC composite shows the nanostructure of BC with a length of fiber around 35-60 nm in width. The SEM-EDX micrograph showed that silver particles were impregnated into the BC matrix. Antibacterial activity test results showed that the Ag-BC composite had the ability to inhibit the bacteria S. typhimurium and S. aureus with good inhibition. This result showed the potential application of Ag-BC composite from Siwalan plant as a natural material for medical and pharmaceutical purpose, especially as an antibacterial agent.

scholarly journals A Preliminary Investigation on the In-Vitro Antibacterial Activities of Cave Actinomycetes

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Asifa Mushtaq ◽  
Musharaf Gul ◽  
Seema Rawat ◽  
Jay Krishan Tiwari
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Scientific Community ◽  
Preliminary Investigation ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Industrial Applications ◽  
Gram Positive Bacteria ◽  
Streptomyces Genus

Actinomycetes are prolific producers of secondary metabolites majority of which have phenomenal industrial applications. Actinomycetes recovered from cave habitats have generated a considerable interest among the scientific community with respect to their adaptability under such unique environmental conditions. Garhwal Himalaya, Uttarakhand abodes several pristine caves which have not been previously explored for the presence of actinomycetes. The present study has been undertaken to assess the in vitro antibacterial properties of actinomycetes recovered from some of the caves located in Garhwal Himalayan region. In the present study, a total of 127 actinomycetes were isolated from three distinct caves. Majority of the isolates exhibited antibacterial activity against gram-positive bacteria. Actinomycetes isolates RCM1 and SCMM1 were observed to evince promising antibacterial activities. Members of Streptomyces genus were found to be predominant in all the samples.

Antibacterial activity and cell compatibility of TiZrN, TiZrCN, and TiZr-amorphous carbon coatings

2015 ◽  
Vol 596 ◽  
pp. 111-117 ◽  
Author(s):  
Heng-Li Huang ◽  
Yin-Yu Chang ◽  
Jia-Xu Liu ◽  
Ming-Tzu Tsai ◽  
Chih-Ho Lai
Keyword(s):  
Antibacterial Activity ◽  
Amorphous Carbon ◽  
Carbon Coatings ◽  
Cell Compatibility ◽  
Amorphous Carbon Coatings

scholarly journals Antibacterial activity of ethanolic extracts of some moss species

2017 ◽  
Vol 63 (3) ◽  
pp. 11-17 ◽  
Author(s):  
Tomasz M. Karpiński ◽  
Artur Adamczak
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Moss Species ◽  
Gram Positive Bacteria ◽  
Agar Disc ◽  
Ethanolic Extracts ◽  
Antiviral Activities ◽  
First Time

Summary Introduction: For centuries, mosses have been used in traditional medicine due to their antibacterial, antifungal, and antiviral activities. Objective: The present study was designed to evaluate the antibacterial activity of ethanolic extracts obtained from 12 moss species: Brachythecium albicans, Bryum argenteum, Ceratodon purpureus, Dicranum scoparium, Dryptodon pulvinatus, Orthotrichum anomalum, Oxyrrhynchium hians, Plagiomnium undulatum, Polytrichum juniperinum, P. piliferum, Schistidium crassipilum, and Syntrichia ruralis. Methods: The antimicrobial activity of extracts was investigated against three Gram(+) bacteria (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes) and two Gram(-) bacteria (Escherichia coli and Klebsiella pneumoniae), using the agar disc-diffusion method. Results: The high activity against all investigated bacteria was determined for extracts of D. pulvinatus, P. undulatum, B. argenteum, S. crassipilum, O. anomalum (mean inhibition zone: 11.3-13.1 mm) and to a lesser extent in the case of D. scoparium (8.3 mm). Extracts from P. juniperinum and P. piliferum showed activity only against Gram-positive bacteria, with an inhibition zone from 7.3 to 9.7 mm. Four species: B. albicans, C. purpureus, O. hians, and S. ruralis had not antibacterial properties. Conclusions: The obtained results indicate that mosses could be a significant source of antibacterial agents. For the first time, we presented antibacterial activity of ethanolic extracts from S. crassipilum and O. anomalum.

scholarly journals Silver Doped Magnesium Ferrite Nanoparticles: Physico-Chemical Characterization and Antibacterial Activity

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2859
Author(s):  
Erika Fantozzi ◽  
Erlinda Rama ◽  
Cinzia Calvio ◽  
Benedetta Albini ◽  
Pietro Galinetto ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Spinel Phase ◽  
Sol Gel ◽  
Antibacterial Properties ◽  
Chemical Characterization ◽  
Metallic Silver ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Physico Chemical ◽  
And Staphylococcus Aureus

Spinel phases, with unique and outstanding physical properties, are attracting a great deal of interest in many fields. In particular, MgFe2O4, a partially inverted spinel phase, could find applications in medicine thanks to the remarkable antibacterial properties attributed to the generation of reactive oxygen species. In this paper, undoped and Ag-doped MgFe2-xAgxO4 (x = 0.1 and 0.3) nanoparticles were prepared using microwave-assisted combustion and sol–gel methods. X-ray powder diffraction, with Rietveld structural refinements combined with micro-Raman spectroscopy, allowed to determine sample purity and the inversion degree of the spinel, passing from about 0.4 to 0.7 when Ag was introduced as dopant. The results are discussed in view of the antibacterial activity towards Escherichia coli and Staphylococcus aureus, representative strains of Gram-negative and Gram-positive bacteria. The sol–gel particles were more efficient towards the chosen bacteria, possibly thanks to the nanometric sizes of metallic silver, which were well distributed in the powders and in the spinel phase, with respect to microwave ones, that, however, acquired antibacterial activity after thermal treatment, probably due to the nucleation of hematite, itself displaying well-known antibacterial properties and which could synergistically act with silver and spinel.

Antibacterial activity of casein-derived peptides isolated from rabbit (Oryctolagus cuniculus) milk

2003 ◽  
Vol 70 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Maria Baranyi ◽  
Ursula Thomas ◽  
Antonio Pellegrini
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Milk Proteins ◽  
Reversed Phase ◽  
Antibacterial Peptides ◽  
Proteolytic Digestion ◽  
Peptide Fragments ◽  
Gram Positive Bacteria ◽  
Micro Organisms

Acid-precipitated rabbit ‘whole casein’ was digested by trypsin, chymotrypsin, pepsin, and clostripain to screen for possible peptides with antibacterial properties. The peptide fragments were separated by reversed-phase chromatography. The collected fractions were pooled and their antibacterial properties tested against Escherichia coli, Bacillus subtilis and Staphylococcus lentus. Three antibacterial peptide fragments derived from tryptic digestion of rabbit casein were isolated and identified. Their sequences were found as follows: HVEQLLR (residues 50–56 of β-casein), ILPFIQSLFPFAER (residues 64–77 of β-casein), and FHLGHLK (residues 19–25 of αs1-casein). The three peptides were synthesized and found to exert antibacterial effect against Gram positive bacteria only. Proteolytic digestion of rabbit casein by chymotrypsin, pepsin and clostripain yielded several peptide fragments with antibacterial activity. Since antibiotic peptides can be released from casein during the digestion of milk proteins, our results suggest a possible antibacterial function of rabbit caseins. It is conceivable that antibacterial peptides can be generated by endopeptidases of the mammalian gastrointestinal tract possibly providing protection for new-born rabbits against aggression of micro-organisms.

scholarly journals ANTIBACTERIAL ACTIVITY OF “ANASTATICA HIEROCHUNTICA L.” AGAINST SOME BACTERIAL STRAINS RESPONSIBLE FOR WOMEN’S URO-GENITAL INFECTION

2018 ◽  
Vol 11 (7) ◽  
pp. 222
Author(s):  
Elhassan Benyagoub ◽  
Nouria Nabbou ◽  
Dalila Razni ◽  
Snoussi Moghtet
Keyword(s):  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Antibacterial Properties ◽  
Genital Infection ◽  
Bacterial Strains ◽  
Resistance Profile ◽  
Gram Positive Bacteria ◽  
Natural Substances ◽  
Antibiotic Resistance Profile ◽  
Antibacterial Potential

Objective: The purpose of this work is to study the biological activity of Anastatica hierochuntica L., against nine bacterial strains responsible for women’s uro-genital infection (UGI).Methods: The plant was collected from Tindouf region (far southwest Algeria). In this study, we performed an evaluation of antibacterial activity of three macerates of two vegetative parts (seeds and stems) by two methods (disc and wells diffusion methods), with a description of the antibiotic resistance profile of isolated bacterial strains by antibiogram method.Results: According to the results, the antibiotic resistance profile of the tested bacterial strains showed an increased resistance against several antibiotics families. The evaluation of the antibacterial potential of macerates showed that methanolic and aqueous macerates of the seeds were more active against Gram-positive bacteria compared to Gram-negative bacteria.Conclusion: The preliminary results of this study allowed us to predict that natural substances in the plant can be considered as an important source to possess compounds with significant antibacterial properties and thus suggest their application in the pharmaceutical industry.

Evaluation of the Antibacterial Activity of Ag- and Au-Nanoparticles Loaded TiO2 Nanotubes

2020 ◽  
Vol 16 (9) ◽  
pp. 1416-1425
Author(s):  
Katarzyna Arkusz ◽  
Ewa Paradowska ◽  
Marta Nycz ◽  
Justyna Mazurek-Popczyk ◽  
Katarzyna Baldy-Chudzik
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Live Bacteria

Current research on the antibacterial properties of implant surfaces has focused on using titanium nanotubes (TNTs) with diameters of 100 and 200 nm, which simultaneously show the best antibacterial properties, poor osseointegration, and ability to immobilize proteins. Therefore, the research aimed to develop an implantable material based on titanium dioxide nanotubes with a diameter of 50 nm doped with silver (AgNPs) and gold nanoparticles (AuNPs), indicating good absorption and antibacterial properties. Moreover, metallic nanoparticles deposited by varying methods should maintain sphericity and lack of agglomeration. For this purpose, the surface charge, wettability, stability of nanoparticles, and antibacterial properties against Gram-positive and Gram-negative bacteria, i. e., Staphylococcus epidermidis, Streptococcus mutans, and Pseudomonas aeruginosa , were performed. Obtained results indicate a greater resistance to leaching of silver nanoparticles compared to gold nanoparticles. These results are reflected in microbiological studies, both into the time and the effectiveness of the implantable material's antibacterial activity. A greater antibacterial effect of AgNPs than AuNPs has been confirmed. Also, AgNPs inhibit the multiplication of Gram-negative bacteria to a greater extent than Gram-positive bacteria. It has been proven that the TNT platforms deposited with metal nanoparticles via the voltammetric method are more effective in deactivating microorganisms. Besides, the results have proven that smaller TNTs effectively reduce live bacteria as nanotubes with a diameter of 100 and 200 nm.

scholarly journals Preparation of nanocomposite silver/kaolin with antibacterial properties

2021 ◽  
Vol 340 ◽  
pp. 01030
Author(s):  
Balnur Baltabayeva ◽  
Aliya Ospanova ◽  
Zhanar Kubasheva
Keyword(s):  
Antibacterial Activity ◽  
Chemical Reduction ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Silica Matrix ◽  
Gram Positive Bacteria ◽  
Composition And Structure ◽  
Bet Method ◽  
Mobile Ions ◽  
Physical And Chemical

In this study, a nanocomposite based on kaolin from the Alekseevsky deposit (Kazakhstan), containing nano-silver particles, was synthesized. Kaolin has good physical and chemical properties and is an effective carrier for medicines. The synthesis of AgNPs/kaolin nanocomposites was carried out by chemical reduction. Impregnation of silver nanoparticles into silica matrix can prevent the agglomeration of mobile ions, and thereby preserve the antibacterial activity of the compound. The composition and structure of the resulting nanocomposite were studied using SEM/EDS analysis to study the morphology and elemental composition of natural and silver-modified kaolin, the specific surface was determined by the BET method, and functional groups were identified by IR spectroscopy. The resulting composite was tested for antibacterial activity against Gram-negative and Gram-positive bacteria (E.Сoli, S. Aureus).

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