Bacterial cellulose films with ZnO nanoparticles and propolis extracts: Synergistic antimicrobial effect

AbstractThis study aimed to obtain possible materials for future antimicrobial food packaging applications based on biodegradable bacterial cellulose (BC). BC is a fermentation product obtained by Gluconacetobacter xylinum using food or agricultural wastes as substrate. In this work we investigated the synergistic effect of zinc oxide nanoparticles (ZnO NPs) and propolis extracts deposited on BC. ZnO NPs were generated in the presence of ultrasounds directly on the surface of BC films. The BC-ZnO composites were further impregnated with ethanolic propolis extracts (EEP) with different concentrations.The composition of raw propolis and EEP were previously determined by gas-chromatography mass-spectrometry (GC-MS), while the antioxidant activity was evaluated by TEAC (Trolox equivalent antioxidant capacity). The analysis methods performed on BC-ZnO composites such as scanning electron microscopy (SEM), thermo-gravimetrically analysis (TGA), and energy-dispersive X-ray spectroscopy (EDX) proved that ZnO NPs were formed and embedded in the whole structure of BC films. The BC-ZnO-propolis films were characterized by SEM and X-ray photon spectroscopy (XPS) in order to investigate the surface modifications. The antimicrobial synergistic effect of the BC-ZnO-propolis films were evaluated against Escherichia coli, Bacillus subtilis, and Candida albicans. The experimental results revealed that BC-ZnO had no influence on Gram-negative and eukaryotic cells.

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Effect of Drying Methods on Structure and Mechanical Properties of Bacterial Cellulose Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2667 ◽

2011 ◽

Vol 239-242 ◽

pp. 2667-2670 ◽

Cited By ~ 5

Author(s):

Chuan Jie Zhang ◽

Liu Wang ◽

Jin Chao Zhao ◽

Ping Zhu

Keyword(s):

Mechanical Properties ◽

Bacterial Cellulose ◽

Degree Of Crystallinity ◽

Drying Methods ◽

Hot Air Drying ◽

Air Drying ◽

X Ray ◽

Cellulose Films ◽

Hot Air ◽

Vacuum Freezing

Bacterial cellulose (BC) gelatinous films prepared in stationary culture were dried by three different drying methods: hot air drying, vacuum drying and vacuum freezing drying. The structure of dried bacterial cellulose films was characterized using scanning electron microscopy (SEM), infrared spectroscopy (IR) and X-ray diffraction (XRD), and mechanical properties were tested. The results showed that the surface of films prepared by hot air drying were uniform and dense, cavities and cracks configurations existed in vacuum dried films, and layer and porous structures were observed in vacuum freezing dried films. FTIR spectra and X-ray pattern confirmed that vacuum freezing drying reduced the strength of hydrogen bonds between cellulose macromolecules and the degree of crystallinity of BC films but had little influence on the crystal structure. For those reasons, mechanical properties of BC films prepared by vacuum freezing drying were lower than that of those films by other methods.

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Modelling of sorbic acid diffusion through bacterial cellulose-based antimicrobial films

Chemical Papers ◽

10.2478/s11696-011-0086-2 ◽

2012 ◽

Vol 66 (2) ◽

Cited By ~ 15

Author(s):

Loredana-Mihaela Dobre ◽

Anicuţa Stoica-Guzun ◽

Marta Stroescu ◽

Iuliana Jipa ◽

Tǎnase Dobre ◽

...

Keyword(s):

Bacterial Cellulose ◽

Food Packaging ◽

Sorbic Acid ◽

Composite Films ◽

Antimicrobial Properties ◽

Antimicrobial Effect ◽

Poly Vinyl Alcohol ◽

Packaging Materials ◽

Biocomposite Films ◽

Swelling Rate

AbstractAntimicrobial packaging protects the product from the external environment and microbial contamination, conferring numerous advantages on human health. Interest in biopolymers as packaging materials has considerably increased recently. Bacterial cellulose is an interesting biomaterial produced as nanofibrils by Acetobacter xylinium and is a promising candidate due to its remarkable properties. New composite materials with antimicrobial properties were developed in this work, containing poly(vinyl alcohol) (PVA) as polymer matrix and ground bacterial cellulose (BC) as reinforcing fibres. Sorbic acid was used as an antimicrobial agent because it is a preservative recognised in the food industry. The materials obtained were studied using Fourier-transformed infrared spectroscopy (FTIR). The swelling rate of the composites was also measured. Release experiments of sorbic acid from the composite films into water were performed and the mass transfer phenomena were investigated using Fick’s law of diffusion. The antimicrobial effect was tested against Escherichia coli K12-MG1655. The results obtained indicated that the new biocomposite films could be promising antimicrobial food packaging materials.

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Properties of nanocomposites based on isotactic polypropylene and high-pressure polyethylene with metal-containing nanofillers

Perspektivnye Materialy ◽

10.30791/1028-978x-2020-9-59-64 ◽

2020 ◽

pp. 59-64

Author(s):

N. I. Kurbanova ◽

◽

T. M. Gulieva ◽

N. Ya. Ischenko ◽

◽

...

Keyword(s):

High Pressure ◽

Synergistic Effect ◽

Polymer Matrix ◽

Isotactic Polypropylene ◽

Rheological Parameters ◽

Mechanochemical Method ◽

X Ray ◽

Effect Of Additives ◽

High Pressure Polyethylene ◽

Properties Of Composites

The effect of additives of nanofillers (NF) containing nanoparticles (NP) of copper oxide, stabilized by a polymer matrix of maleized polyethylene (MPE), obtained by the mechanochemical method, on the properties of composites based on isotactic polypropylene (PP) and high-pressure polyethylene (PE) was studied by X-ray phase (XRD) and thermogravimetric (TGA) analyzes. The enhancement of strength, deformation, and rheological parameters, as well as the thermo-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is due to the synergistic effect of the interaction of copper-containing nanoparticles with anhydride groups of MPE. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing and injection molding and extrusion, which expands the scope of its application.

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Chemical Recycling of WEEE Plastics—Production of High Purity Monocyclic Aromatic Chemicals

Processes ◽

10.3390/pr9030530 ◽

2021 ◽

Vol 9 (3) ◽

pp. 530

Author(s):

Tobias Rieger ◽

Jessen C. Oey ◽

Volodymyr Palchyk ◽

Alexander Hofmann ◽

Matthias Franke ◽

...

Keyword(s):

High Purity ◽

Fractional Distillation ◽

Gas Chromatography Mass Spectrometry ◽

Thermochemical Conversion ◽

Chemical Recycling ◽

Pyrolysis Oil ◽

X Ray ◽

Benzene Toluene ◽

Halogen Content ◽

Methyl Styrene

More than 200 kg real waste electrical and electronic equipment (WEEE) shredder residues from a German dismantling plant were treated at 650 °C in a demonstration scale thermochemical conversion plant. The focus within this work was the generation, purification, and analysis of pyrolysis oil. Subsequent filtration and fractional distillation were combined to yield basic chemicals in high purity. By means of fractional distillation, pure monocyclic aromatic fractions containing benzene, toluene, ethylbenzene, and xylene (BTEX aromatics) as well as styrene and α-methyl styrene were isolated for chemical recycling. Mass balances were determined, and gas chromatography–mass spectrometry (GC-MS) as well as energy dispersive X-ray fluorescence (EDXRF) measurements provided data on the purity and halogen content of each fraction. This work shows that thermochemical conversion and the subsequent refining by fractional distillation is capable of recycling WEEE shredder residues, producing pure BTEX and other monocyclic aromatic fractions. A significant decrease of halogen content (up to 99%) was achieved with the applied methods.

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Wound Healing Composite Materials of Bacterial Cellulose and Zinc Oxide Nanoparticles with Immobilized Betulin Diphosphate

Nanomaterials ◽

10.3390/nano11030713 ◽

2021 ◽

Vol 11 (3) ◽

pp. 713

Author(s):

Nina Melnikova ◽

Alexander Knyazev ◽

Viktor Nikolskiy ◽

Peter Peretyagin ◽

Kseniia Belyaeva ◽

...

Keyword(s):

Wound Healing ◽

Zinc Oxide ◽

Bacterial Cellulose ◽

Zinc Oxide Nanoparticles ◽

Wound Dressings ◽

Oxide Nanoparticles ◽

Burn Wound ◽

Zno Nps ◽

Wound Model ◽

And Oxidative Stress

A design of new nanocomposites of bacterial cellulose (BC) and betulin diphosphate (BDP) pre-impregnated into the surface of zinc oxide nanoparticles (ZnO NPs) for the production of wound dressings is proposed. The sizes of crystalline BC and ZnO NPs (5–25%) corresponded to 5–6 nm and 10–18 nm, respectively (powder X-ray diffractometry (PXRD), Fourier-infrared (FTIR), ultraviolet (UV), atomic absorption (AAS) and photoluminescence (PL) spectroscopies). The biological activity of the wound dressings “BC-ZnO NPs-BDP” was investigated in rats using a burn wound model. Morpho-histological studies have shown that more intensive healing was observed during treatment with hydrophilic nanocomposites than the oleophilic standard (ZnO NPs-BDP oleogel; p < 0.001). Treatment by both hydrophilic and lipophilic agents led to increases in antioxidant enzyme activity (superoxide dismutase (SOD), catalase) in erythrocytes and decreases in the malondialdehyde (MDA) concentration by 7, 10 and 21 days (p < 0.001). The microcirculation index was restored on the 3rd day after burn under treatment with BC-ZnO NPs-BDP wound dressings. The results of effective wound healing with BC-ZnO NPs-BDP nanocomposites can be explained by the synergistic effect of all nanocomposite components, which regulate oxygenation and microcirculation, reducing hypoxia and oxidative stress in a burn wound.

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Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves and Cloves

Foods ◽

10.3390/foods10061406 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1406

Author(s):

Rita Cava-Roda ◽

Amaury Taboada-Rodríguez ◽

Antonio López-Gómez ◽

Ginés Benito Martínez-Hernández ◽

Fulgencio Marín-Iniesta

Keyword(s):

Antimicrobial Activity ◽

Essential Oils ◽

Food Packaging ◽

Antimicrobial Effect ◽

Antimicrobial Activities ◽

Inhibitory Effects ◽

Cinnamon Bark ◽

E Coli ◽

Pure Compounds ◽

Main Component

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

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Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

Polymers ◽

10.3390/polym13132123 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2123

Author(s):

Maria Râpă ◽

Maria Stefan ◽

Paula Popa ◽

Dana Toloman ◽

Cristian Leostean ◽

...

Keyword(s):

Food Packaging ◽

Spin Trapping ◽

X Ray Diffraction ◽

Paramagnetic Resonance ◽

Hno3 Solution ◽

X Ray ◽

Trapping Method ◽

Ft Ir ◽

Doped Zno ◽

Electron Paramagnetic

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

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Biosynthesis of Zinc Oxide Nanoparticles from Acacia nilotica (L.) Extract to Overcome Carbapenem-Resistant Klebsiella Pneumoniae

Molecules ◽

10.3390/molecules26071919 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1919

Author(s):

Elsayim Rasha ◽

AlOthman Monerah ◽

Alkhulaifi Manal ◽

Ali Rehab ◽

Doud Mohammed ◽

...

Keyword(s):

Electron Microscopy ◽

Zinc Oxide ◽

Klebsiella Pneumoniae ◽

Zinc Oxide Nanoparticles ◽

Acacia Nilotica ◽

Oxide Nanoparticles ◽

Zno Nps ◽

X Ray ◽

Carbapenem Resistant

Recently, concerns have been raised globally about antimicrobial resistance, the prevalence of which has increased significantly. Carbapenem-resistant Klebsiella pneumoniae (KPC) is considered one of the most common resistant bacteria, which has spread to ICUs in Saudi Arabia. This study was established to investigate the antibacterial activity of biosynthesized zinc oxide nanoparticles (ZnO-NPs) against KPC in vitro and in vivo. In this study, we used the aqueous extract of Acacia nilotica (L.) fruits to mediate the synthesis of ZnO-NPs. The nanoparticles produced were characterized by UV-vis spectroscopy, zetasizer and zeta potential analyses, X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of ZnO-NPs against KPC was determined via the well diffusion method, and determining minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the results showed low MIC and MBC when compared with the MIC and MBC of Imipenem and Meropenem antibiotics. The results of in vitro analysis were supported by the results upon applying ZnO-NP ointment to promote wound closure of rats, which showed better wound healing than the results with imipenem ointment. The biosynthesized ZnO-NPs showed good potential for use against bacteria due to their small size, applicability, and low toxicity to human cells.

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Scolicidal activity of biosynthesized zinc oxide nanoparticles by Mentha longifolia L. leaves against Echinococcus granulosus protoscolices

Emergent Materials ◽

10.1007/s42247-021-00264-9 ◽

2021 ◽

Author(s):

Bushra H. Shnawa ◽

Samir M. Hamad ◽

Azeez A. Barzinjy ◽

Payman A. Kareem ◽

Mukhtar H. Ahmed

Keyword(s):

Zinc Oxide ◽

Zinc Oxide Nanoparticles ◽

Public Health Problem ◽

Analytical Techniques ◽

Oxide Nanoparticles ◽

Zno Nps ◽

Leaf Extracts ◽

X Ray ◽

Morphological Alterations ◽

Mentha Longifolia

AbstractCystic echinococcosis is a public health problem in developing countries that practice sheep breeding extensively. In the current study, the protoscolicidal activity of biosynthesized zinc oxide nanoparticles (ZnO NPs) derived from Mentha longifolia L. leaf extracts was investigated. The resultant ZnO NPs were characterized by means of various analytical techniques, such as ultraviolet–visible (UV–Vis) spectrometry, Fourier transform infrared (FT-IR) spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analysis. The results showed that the ZnO NP had the highest scolicidal activity at 400 ppm concentration after 150 min of exposure time, showing 100% mortality rate. The treated protoscolices exhibited loss of viability with several morphological alterations. Hence, an easy and effective green synthesis of ZnO NPs, with efficient scolicidal potential, is reported in this study.

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Decoration of CuO NWs Gas Sensor with ZnO NPs for Improving NO2 Sensing Characteristics

Sensors ◽

10.3390/s21062103 ◽

2021 ◽

Vol 21 (6) ◽

pp. 2103 ◽

Cited By ~ 1

Author(s):

Tae-Hee Han ◽

So-Young Bak ◽

Sangwoo Kim ◽

Se Hyeong Lee ◽

Ye-Ji Han ◽

...

Keyword(s):

Gas Sensor ◽

Gas Sensors ◽

Sol Gel ◽

Oxide Semiconductor ◽

Zno Nps ◽

X Ray ◽

Semiconductor Gas Sensor ◽

Initial Resistance ◽

P Type ◽

Sensing Characteristics

This paper introduces a method for improving the sensitivity to NO2 gas of a p-type metal oxide semiconductor gas sensor. The gas sensor was fabricated using CuO nanowires (NWs) grown through thermal oxidation and decorated with ZnO nanoparticles (NPs) using a sol-gel method. The CuO gas sensor with a ZnO heterojunction exhibited better sensitivity to NO2 gas than the pristine CuO gas sensor. The heterojunction in CuO/ZnO gas sensors caused a decrease in the width of the hole accumulation layer (HAL) and an increase in the initial resistance. The possibility to influence the width of the HAL helped improve the NO2 sensing characteristics of the gas sensor. The growth morphology, atomic composition, and crystal structure of the gas sensors were analyzed using field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy, and X-ray diffraction, respectively.

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