Effect of Cu Nanoparticles on the Properties of PP-g-PHMG/PE Monofilament and Its Antifouling Application

The modified polyethylene monofilament was prepared by melt blending and spinning using polyethylene (PE), polypropylene-grafted poly(hexamethylene guanidine) (PP-g-PHMG), and Cu nanoparticles (CuNPs). The effect of CuNP content on the structure, mechanical properties, and antimicrobial properties of the monofilaments was studied. In addition, the antifouling property of fishing nets using the modified polyethylene monofilaments was evaluated. The results showed that CuNPs were dispersed homogeneously in the monofilament matrix as microaggregates. The initial increase in the tensile strength of monofilament was attributed to the mechanical restraint, whereas a decrease in the tensile properties at 1.0 wt% CuNP content was due to the predominant effect of a decrease in the total crystallinity. A bacteriostatic test showed that the monofilament had an obvious inhibitory effect on Staphylococcus aureus. Furthermore, coupon test results showed that PP-g-PHMG/PE/CuNP nanocomposite netting had lower weight gain than PP-g-PHMG/PE netting (23.6% reduction) because of the combined antibacterial effect of both PHMG and CuNP. Therefore, PP-g-PHMG/PE/CuNP monofilament has the potential to produce green and efficient antifouling fishing nets.

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Polypropylene-Grafted Poly(hexamethylene guanidine)/Modified Polyethylene Monofilament and Its Antimicrobial Performance

International Journal of Polymer Science ◽

10.1155/2020/6416230 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Yue Wang ◽

Wenwen Yu ◽

Aiyan Shu ◽

Jiangao Shi ◽

Min Zhang

Keyword(s):

Mechanical Properties ◽

Breaking Strength ◽

Antimicrobial Properties ◽

Inhibitory Effect ◽

Degree Of Crystallinity ◽

Total Degree ◽

Crystalline Region ◽

Melt Blending ◽

E Coli ◽

Antimicrobial Performance

A polypropylene-grafted poly(hexamethylene guanidine) (PP-g-PHMG)/polyethylene (PE) monofilament was prepared by melt blending and spinning using PE and PP-g-PHMG. The effect of PP-g-PHMG content on the structure, mechanical properties, and antimicrobial properties of PP-g-PHMG/PE alloy monofilaments was studied. Compared with PP/PE without grafting PHMG, Tm of PP-g-PHMG/PE alloy monofilaments increased due to rigidity of PHMG grafted. In the PP-g-PHMG/PE alloy monofilaments, the total degree of crystallinity of alloy monofilaments decreased; hence, the α-relaxation associated with the crystalline region of the polymer matrix becomes weaker as PP-g-PHMG content increases. The breaking strength of PP-g-PHMG/PE alloy monofilaments decreased while the knotting strength increased by increasing PP-g-PHMG content. The antibacterial test showed that the PP-g-PHMG/PE alloy monofilament had obvious inhibitory effect on E. coli and Staphylococcus aureus. Therefore, the PP-g-PHMG/PE alloy monofilament has the potential to make green and highly effective antifouling materials.

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Antimicrobial Properties of the Ag, Cu Nanoparticle System

Biology ◽

10.3390/biology10020137 ◽

2021 ◽

Vol 10 (2) ◽

pp. 137

Author(s):

Xinzhen Fan ◽

L’Hocine Yahia ◽

Edward Sacher

Keyword(s):

Reactive Oxygen Species ◽

Biomedical Application ◽

Antimicrobial Properties ◽

Antimicrobial Activities ◽

Oxygen Species ◽

Cu Nanoparticles ◽

Postoperative Infections ◽

Nanoparticle System ◽

Contact Killing ◽

Bacteria And Fungi

Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact their antimicrobial effects. When mixed, the combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag–Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them.

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Pemodelan Kondisi Optimum Ekstraksi dan Identifikasi Senyawa Penyusun Minyak Atsiri Lada Hitam

Jurnal Agro Industri Perkebunan ◽

10.25181/jaip.v9i2.2132 ◽

2021 ◽

pp. 99-108

Author(s):

Shintawati Shintawati ◽

Analianasari Analianasari ◽

Zukryandry Zukryandry

Keyword(s):

Essential Oil ◽

Respiratory Infections ◽

Antimicrobial Properties ◽

Black Pepper ◽

Operating Conditions ◽

Solvent Ratio ◽

Test Results ◽

Optimum Conditions ◽

Muscle Disorders ◽

Surface Method

Black pepper is a spice with a spicy taste and a distinctive aroma that has become known as the King of Spices. The distinctive aroma of black pepper comes from the volatile compounds that make up the essential oil of pepper. Black pepper essential oil has antimicrobial properties that can relieve respiratory infections and relieve muscle disorders. The acquisition of pepper essential oil from the distillation process is influenced by operating conditions. The aim of this study was to identify the composition of black pepper essential oil compounds using GCMS and to optimize the operating conditions (material size, solvent ratio, and distillation time). The method used to determine the optimum condition is using the Response Surface Method (RSM). The results showed that the highest yield of black pepper essential oil from this experiment is 5.14%. The empirical model was also suitable for the experiment and the optimum conditions for producing the maximum pepper oil yield 5,81% were 40 mesh of material size, 0.12 (g.ml-1) of solvent ratio and 162 minutes of distillation time. GCMS test results showed that the main constituents of pepper essential oil are caryophyllene, ocimene, limonene, carene, and a-pinene.

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Antibacterial activity of plant extracts against Listeria monocytogenes isolated from ready-to-eat salads

Acta Universitatis Sapientiae Alimentaria ◽

10.2478/ausal-2020-0008 ◽

2020 ◽

Vol 13 (1) ◽

pp. 131-143

Author(s):

É. György ◽

É. Laslo ◽

E. Csató

Keyword(s):

Listeria Monocytogenes ◽

Essential Oils ◽

Antibacterial Effect ◽

Storage Conditions ◽

Inhibitory Effect ◽

Listeria Innocua ◽

Foodborne Diseases ◽

Bacterial Strains ◽

Antibacterial Effects ◽

Growth Environment

Abstract Ready-to-eat salads are becoming more and more popular. However, due to their ingredients, they represent a suitable growth environment for different microbes. In the prevention of foodborne diseases, hygienic food preparation and appropriate storage conditions are very important. During this study, ten different ready-to-eat salads were analysed for the presence of Listeria monocytogenes. Five different selective agar mediums were used for the enumeration and isolation of Listeria monocytogenes. The isolated bacterial strains were subjected to morphological and biochemical confirmation tests. The antibacterial effects of five different freshly squeezed vegetable juices (carrots, celery, beets, horseradish, and onions) and of five essential oils (dill, thyme, oregano, lemongrass, and sage) were determined against Listeria monocytogenes, Listeria innocua, and L. monocytogenes strains isolated from ready-to-eat salads. Based on the results obtained from fresh vegetable juices, carrot juice exerted the highest antibacterial effect, while the others showed no or slight inhibitory effect (horseradish, beets, onions) against Listeria species. Among the essential oils, thyme, lemongrass, and oregano showed the strongest antibacterial effect against the studied Listeria species.

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The Carpathian lingonberry, raspberry and blackberry fruit extracts feature variable antimicrobial efficiency

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/1/2365 ◽

2019 ◽

pp. 27-32

Author(s):

Emőke Mihok ◽

Éva György ◽

Endre Máthé

Keyword(s):

Antimicrobial Properties ◽

Ethanolic Extract ◽

Inhibitory Effect ◽

Diffusion Method ◽

Gram Positive ◽

Gram Negative ◽

Antimicrobial Effects ◽

Fruit Extracts ◽

Gram Positive Bacteria ◽

Wild Berries

Wild berry is an excellent source of phytonutrients and/or bioactive compounds associated with significant therapeutic properties, so that they have been utilized in folk medicine and traditional nutrition throughout centuries. Multiple health-promoting effects, such as anti-inflammatory, anti-diabetic, anti-heart and coronary disease properties were attributed to such wild berries. It has also been proved that berries could feature antimicrobial effects that could be of a great importance for the prevention of food-feed poisoning and fighting back antibiotic resistance. In this study, we investigated the antimicrobial properties of lingonberry (Vaccinium vitis-idaea), raspberry (Rubus idaeus) and blackberry (Rubus fruticosus) crude and ethanolic extracts prepared from fruits obtained from the spontaneous flora of Eastern Carpathian Mountains situated in Transylvania. The antimicrobial effect of crude and alcoholic extracts were assessed on four Gram-negative, five Gram-positive bacteria and one yeast species using the agar diffusion method. The studied bacteria can cause food or feed spoilage and foodborne diseases. Our results indicate the significant inhibitory effect of lingonberry extracts in the case of Gram-negative bacteria like Proteus vulgaris and Salmonella Hartford, while among Gram-positive bacteria the strongest inhibitory effect was observed for Bacillus species like B. cereus, B. subtilis, B. mojavensis and Micrococcus luteus. The raspberry and blackberry extracts featured milder inhibitory effects in the case of the studied bacteria species. Furthermore, we have studied the crude or ethanolic extract combinations associated antimicrobial effects synergistic/additive or antagonistic properties. Interestingly, the triple and double ethanolic extract mixes had stronger antimicrobial properties, whereas the crude extract mixes showed relatively reduced effects, if any. Our results indicate that the antimicrobial activity of studied fruit extracts obtained from wild berries can vary upon the applied extraction method and their combination formulae, so that all these considerations must be taken into account when such fruit extracts are considered for foodstuff development.

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Zinc oxide nanoparticles prepared by thermal decomposition of zinc benzenepolycarboxylato precursors: Photoluminescent, photocatalytic and antimicrobial properties

Journal of the Serbian Chemical Society ◽

10.2298/jsc200629048r ◽

2020 ◽

Vol 85 (11) ◽

pp. 1475-1488

Author(s):

Lidija Radovanovic ◽

Jelena Zdravkovic ◽

Bojana Simovic ◽

Zeljko Radovanovic ◽

Katarina Mihajlovski ◽

...

Keyword(s):

Thermal Decomposition ◽

Zinc Oxide ◽

Zno Nanoparticles ◽

Diffuse Reflectance Spectroscopy ◽

Antimicrobial Properties ◽

Average Crystallite Size ◽

Hexagonal Wurtzite Structure ◽

Inhibitory Effect ◽

Reactive Orange 16 ◽

Air Atmosphere

Zinc oxide (ZnO) nanoparticles were obtained by thermal decomposition of one-dimensional zinc?benzenepolycarboxylato complexes as single- -source precursors at 450 ?C in an air atmosphere. The mechanism and kinetics of thermal degradation of zinc?benzenepolycarboxylato complexes were analyzed under non-isothermal conditions in an air atmosphere. The results of X-ray powder diffraction and field emission scanning electron microscopy revealed hexagonal wurtzite structure of ZnO with an average crystallite size in the range of 39?47 nm and similar morphology. The band gap and the specific surface area of ZnO nanoparticles were determined using UV?Vis diffuse reflectance spectroscopy and the Brunauer, Emmett and Teller method, respectively. The photoluminescent, photocatalytic and antimicrobial properties of the ZnO nanoparticles were also examined. The best photocatalytic activity in the degradation of C. I. Reactive Orange 16 dye was observed for the ZnO powder where the crystallites form the smallest agglomerates. All ZnO nanoparticles showed excellent inhibitory effect against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli.

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Chemical and Biological Profile and Allergenicity of Thymus baicalensis Plant of Mongolian Origin

Antioxidants ◽

10.3390/antiox10121905 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1905

Author(s):

Tuya Narangerel ◽

Michał Sójka ◽

Radosław Bonikowski ◽

Konrad Jastrząbek ◽

Witold Sroczyński ◽

...

Keyword(s):

Unsaturated Fatty Acids ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Antimicrobial Properties ◽

Volatile Oil ◽

Inhibitory Effect ◽

Food Supplement ◽

Oil Composition ◽

Polyphenolic Composition ◽

Health Promoting

Thymus baicalensis is a medicinal plant recognized as a traditional Mongolian therapeutic and health-promoting food supplement. The aim of the study was to check the suitability of the tested plant for supporting the treatment of certain diseases. The following study is the first one to showcase the versatile scope of characteristics of T. baicalensis, including its volatile oil composition, polyphenolic composition, lipid composition, phenolic and flavonoid contents, antioxidant activity, antimicrobial properties and ingestive allergenicity. Myrcene, at 26.15%, was shown to be the most abundant component of the volatile oil. Compounds known as inherent components of the Thymus genus: thymol and carvacrol made up only about 0.24% of the extracted oil. As much as 10.11 g kg−1 of polyphenol compounds were identified as derivatives of luteolin-7-O-glucuronide. The lipid extract was found to be rich in palmitic acid (31.05%), while unsaturated fatty acids were not reported. Spectrophotometric determination of the phenols and flavonoids indicated 7.541 mg of gallic acid g−1 and 4.345 mg of quercitin g−1, respectively. The free radical scavenging activity was determined by the 2,2-difenylo-1-pikrylohydrazyl method at IC50 = 206.97 µg mL−1. The extracts also had a strong inhibitory effect on M. flavus and P. fluorescenes bacteria, as well as S. cerevisiae yeasts. The Bet v 1 and profilin allergens in T. baicalensis were reported at 175.17 ng g−1 and 1.66 ng g−1, respectively.

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Antioxidant and Antimicrobial Properties of the Fir Buds Syrup

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Food Science and Technology ◽

10.15835/buasvmcn-fst:10123 ◽

2014 ◽

Vol 71 (1) ◽

pp. 77 ◽

Cited By ~ 1

Author(s):

Liana Mariana Deac ◽

Anca Farcas ◽

Dan C. Vodnar ◽

Maria Tofana ◽

Sonia Socaci

Keyword(s):

Vitamin C ◽

Traditional Medicine ◽

Respiratory Diseases ◽

Antimicrobial Properties ◽

Inhibitory Effect ◽

Childhood Disorders ◽

Cold Pressed

The fir buds as well as the fir buds extracts (such as fir buds syrup) are used in traditional medicine and phytotheraphy for the alleviation of light to medium forms of respiratory diseases and for the prophylaxis or treatment of some childhood disorders. The antioxidant and antimicrobial properties of the two types fir buds syrups (cold pressed and boiled) taken into study were demonstrated by its content in vitamin C, flavonoids and by the inhibitory effect on E.coli, B. cereus, S.aureus, L. monocytogenes, Salmonella thypi.

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On Flexural Performance of Girder-To-Girder Wet Joint for Lightweight Steel-UHPC Composite Bridge

Applied Sciences ◽

10.3390/app10041335 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1335 ◽

Cited By ~ 2

Author(s):

Shuwen Deng ◽

Xudong Shao ◽

Banfu Yan ◽

Yan Wang ◽

Huihui Li

Keyword(s):

High Performance ◽

High Performance Concrete ◽

Bending Moment ◽

Inhibitory Effect ◽

Careful Consideration ◽

Joint Interface ◽

Test Results ◽

Negative Moment ◽

Composite Bridge ◽

Negative Bending

Joints are always the focus of the precast structure for accelerated bridge construction. In this paper, a girder-to-girder joint suitable for steel-ultra-high-performance concrete (UHPC) lightweight composite bridge (LWCB) is proposed. Two flexural tests were conducted to verify the effectiveness of the proposed T-shaped girder-to-girder joint. The test results indicated that: (1) The T-shaped joint has a better cracking resistance than the traditional I-shaped joint; (2) The weak interfaces of the T-shaped joint are set in the areas with relatively lower negative bending moment, and thus the cracking risk could be decreased drastically; (3) The natural curing scheme for the joint is feasible, and the reinforcement has a very large inhibitory effect on the UHPC material shrinkage; The joint interface is the weak region of the LWCB, which requires careful consideration in future designs. Based on the experimental test results, the design and calculation methods for the deflection, crack width, and ultimate flexural capacity in the negative moment region of LWCB were presented.

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Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance

Nanomaterials ◽

10.3390/nano10020349 ◽

2020 ◽

Vol 10 (2) ◽

pp. 349 ◽

Cited By ~ 2

Author(s):

Inês Borges ◽

Patrícia C. Henriques ◽

Rita N. Gomes ◽

Artur M. Pinto ◽

Manuel Pestana ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Bacterial Adhesion ◽

Antibacterial Effect ◽

Composite Layer ◽

Dip Coating ◽

Homogeneous Layer ◽

Melt Blending ◽

Bacteria Growth ◽

Antimicrobial Performance ◽

Antibacterial Potential

Catheter-related infections are a common worldwide health problem, highlighting the need for antimicrobial catheters. Here, antibacterial potential of graphene nanoplatelets (GNP) incorporated in the commonly used polymer for catheter manufacture—polyurethane (PU)—is investigated. Two strategies are explored: melt-blending, producing a composite, and dip coating, where a composite layer is deposited on top of PU. GNP with different lateral sizes and oxidation degrees—GNP-M5, GNP-M15, GNP-M5ox, GNP-M15ox—are applied in both strategies, and the antimicrobial potential towards Staphylococcus epidermidis of GNP dispersions and GNP-containing PU evaluated. As dispersions, oxidized and smaller GNP powders (GNP-M5ox) inhibit 74% bacteria growth at 128 µg/mL. As surfaces, GNP exposure strongly impacts their antimicrobial profile: GNP absence at the surface of composites yields no significant effects on bacteria, while by varying GNP: PU ratio and GNP concentration, coatings enhance GNP exposure, depicting an antimicrobial profile. Oxidized GNP-containing coatings induce higher antibacterial effect than non-oxidized forms, particularly with smaller GNPox, where a homogeneous layer of fused platelets is formed on PU, leading to 70% reduction in bacterial adhesion and 70% bacterial death. This pioneering work unravels how to turn a polymer clinically used to produce catheters into an antimicrobial surface, crucial to reducing risk of infection associated with catheterization.

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