Fluoroplast Doped by Ag2O Nanoparticles as New Repairing Non-Cytotoxic Antibacterial Coating for Meat Industry

Foodborne infections are an important global health problem due to their high prevalence and potential for severe complications. Bacterial contamination of meat during processing at the enterprise can be a source of foodborne infections. Polymeric coatings with antibacterial properties can be applied to prevent bacterial contamination. A composite coating based on fluoroplast and Ag₂O NPs can serve as such a coating. In present study, we, for the first time, created a composite coating based on fluoroplast and Ag₂O NPs. Using laser ablation in water, we obtained spherical Ag₂O NPs with an average size of 45 nm and a ζ-potential of -32 mV. The resulting Ag₂O NPs at concentrations of 0.001-0.1% were transferred into acetone and mixed with a fluoroplast-based varnish. The developed coating made it possible to completely eliminate damage to a Teflon cutting board. The fluoroplast/Ag₂O NP coating was free of defects and inhomogeneities at the nano level. The fluoroplast/Ag₂O NP composite increased the production of ROS (H₂O₂, OH radical), 8-oxogualnine in DNA in vitro, and long-lived active forms of proteins. The effect depended on the mass fraction of the added Ag₂O NPs. The 0.01-0.1% fluoroplast/NP Ag₂O coating exhibited excellent bacteriostatic and bactericidal properties against both Gram-positive and Gram-negative bacteria but did not affect the viability of eukaryotic cells. The developed PTFE/NP Ag₂O 0.01-0.1% coating can be used to protect cutting boards from bacterial contamination in the meat processing industry.

Composite Coating for the Food Industry Based on Fluoroplast and ZnO-NPs: Physical and Chemical Properties, Antibacterial and Antibiofilm Activity, Cytotoxicity

Bacterial contamination of meat products during its preparation at the enterprise is an important problem for the global food industry. Cutting boards are one of the main sources of infection. In order to solve this problem, the creation of mechanically stable coatings with antibacterial activity is one of the most promising strategies. For such a coating, we developed a composite material based on "liquid" Teflon and zinc oxide nanoparticles (ZnO-NPs). The nanoparticles obtained with laser ablation had a rod-like morphology, an average size of ~60 nm, and a ζ-potential of +30 mV. The polymer composite material was obtained by adding the ZnO-NPs to the polymer matrix at a concentration of 0.001-0.1% using the low-temperature technology developed by the research team. When applying a composite material to a surface with damage, the elimination of defects on a micrometer scale was observed. The effect of the composite material on the generation of reactive oxygen species (H₂O₂, •OH), 8-oxoguanine in DNA in vitro, and long-lived reactive protein species (LRPS) was evaluated. The composite coating increased the generation of all of the studied compounds by 50-200%. The effect depended on the concentration of added ZnO-NPs. The antibacterial and antibiofilm effects of the Teflon/ZnO NP coating against L. monocytogenes, S. aureus, P. aeruginosa, and S. typhimurium, as well as cytotoxicity against the primary culture of mouse fibroblasts, were studied. The conducted microbiological study showed that the fluoroplast/ZnO-NPs coating has a strong bacteriostatic effect against both Gram-positive and Gram-negative bacteria. In addition, the fluoroplast/ZnO-NPs composite material only showed potential cytotoxicity against primary mammalian cell culture at a concentration of 0.1%. Thus, a composite material has been obtained, the use of which may be promising for the creation of antibacterial coatings in the meat processing industry.

Ag2O Nanoparticles as a Candidate for Antimicrobial Compounds of the New Generation

Antibiotic resistance in microorganisms is an important problem of modern medicine which can be solved by searching for antimicrobial preparations of the new generation. Nanoparticles (NPs) of metals and their oxides are the most promising candidates for the role of such preparations. In the last few years, the number of studies devoted to the antimicrobial properties of silver oxide NPs have been actively growing. Although the total number of such studies is still not very high, it is quickly increasing. Advantages of silver oxide NPs are the relative easiness of production, low cost, high antibacterial and antifungal activities and low cytotoxicity to eukaryotic cells. This review intends to provide readers with the latest information about the antimicrobial properties of silver oxide NPs: sensitive organisms, mechanisms of action on microorganisms and further prospects for improving the antimicrobial properties.

Synthesis of a Novel, Biocompatible and Bacteriostatic Borosiloxane Composition with Silver Oxide Nanoparticles

Microbial antibiotic resistance is an important global world health problem. Recently, an interest in nanoparticles (NPs) of silver oxides as compounds with antibacterial potential has significantly increased. From a practical point of view, composites of silver oxide NPs and biocompatible material are of interest. A borosiloxane (BS) can be used as one such material. A composite material combining BS and silver oxide NPs has been synthesized. Composites containing BS have adjustable viscoelastic properties. The silver oxide NPs synthesized by laser ablation have a size of ~65 nm (half-width 60 nm) and an elemental composition of Ag₂O. The synthesized material exhibits strong bacteriostatic properties against E. coli at a concentration of nanoparticles of silver oxide more than 0.01%. The bacteriostatic effect depends on the silver oxide NPs concentration in the matrix. The BS/silver oxide NPs have no cytotoxic effect on a eukaryotic cell culture when the concentration of nanoparticles of silver oxide is less than 0.1%. The use of the resulting composite based on BS and silver oxide NPs as a reusable dry disinfectant is due to its low toxicity and bacteriostatic activity and its characteristics are not inferior to the medical alloy nitinol.

[Efficacy and safety of a fixed combination drug Brinzolol Duo in the treatment of patients with primary open-angle glaucoma]

PURPOSE

To evaluate the efficacy and safety of a new fixed combination of brinzolamide and timolol in patients with stages I and II of primary open-angle glaucoma (POAG).

MATERIAL AND METHODS

Study patients were divided into 2 groups. The patients of the first group were prescribed Brinzolol Duo, the second group received an original drug Azarga. Regimen for both drugs was 1 drop 2 times per day for 84 days. The study included 7 monitoring visits: visit 0 (screening - 124 patients), visit 1 (randomization and treatment initiation - 120 patients), visits 2-4 (therapy), visit 5 (end of therapy - 117 patients), visit 6 (follow-up, study completion).

RESULTS

Out of 120 patients included in the study, 117 subjects had completed all study procedures. It was shown that both compared drugs significantly reduce intraocular pressure (IOP). After 3 months, 46.5% of patients in the Brinzolol Duo group and 46.9% of patients in the Azarga group had IOP lowered by more than 30% compared to baseline, with IOP amounting to ≤18 mm Hg in 36.6% and 30.2% of patients, respectively. Hypotensive efficacy and safety of the drugs were comparable between the groups (p>0.05). The drugs were well tolerated, all adverse events (AEs) were mild or moderate in severity.

CONCLUSION

The new drug Brinzolol Duo (brinzolamide + timolol) significantly reduces IOP in POAG patients with efficacy comparable to Azarga.

Bacteriostatic and Cytotoxic Properties of Composite Material Based on ZnO Nanoparticles in PLGA Obtained by Low Temperature Method

A low-temperature technology was developed for producing a nanocomposite based on poly (lactic-co-glycolic acid) and zinc oxide nanoparticles (ZnO-NPs), synthesized by laser ablation. Nanocomposites were created containing 0.001, 0.01, and 0.1% of zinc oxide nanoparticles with rod-like morphology and a size of 40-70 nm. The surface of the films from the obtained nanomaterial was uniform, without significant defects. Clustering of ZnO-NPs in the PLGA matrix was noted, which increased with an increase in the concentration of the dopant in the polymer. The resulting nanomaterial was capable of generating reactive oxygen species (ROS), such as hydrogen peroxide and hydroxyl radicals. The rate of ROS generation increased with an increase in the concentration of the dopant. It was shown that the synthesized nanocomposite promotes the formation of long-lived reactive protein species, and is also the reason for the appearance of a key biomarker of oxidative stress, 8-oxoguanine, in DNA. The intensity of the process increased with an increase in the concentration of nanoparticles in the matrix. It was found that the nanocomposite exhibits significant bacteriostatic properties, the severity of which depends on the concentration of nanoparticles. In particular, on the surface of the PLGA-ZnO-NPs composite film containing 0.001% nanoparticles, the number of bacterial cells was 50% lower than that of pure PLGA. The surface of the composite is non-toxic to eukaryotic cells and does not interfere with their adhesion, growth, and division. Due to its low cytotoxicity and bacteriostatic properties, this nanocomposite can be used as coatings for packaging in the food industry, additives for textiles, and also as a material for biomedicine.

A Novel Biodegradable Composite Polymer Material Based on PLGA and Silver Oxide Nanoparticles with Unique Physicochemical Properties and Biocompatibility with Mammalian Cells

A method for obtaining a stable colloidal solution of silver oxide nanoparticles has been developed using laser ablation. The method allows one to obtain nanoparticles with a monomodal size distribution and a concentration of more than 108 nanoparticles per mL. On the basis of the obtained nanoparticles and the PLGA polymer, a nanocomposite material was manufactured. The manufacturing technology allows one to obtain a nanocomposite material without significant defects. Nanoparticles are not evenly distributed in the material and form domains in the composite. Reactive oxygen species (hydrogen peroxide and hydroxyl radical) are intensively generated on the surfaces of the nanocomposite. Additionally, on the surface of the composite material, an intensive formation of protein long-lived active forms is observed. The ELISA method was used to demonstrate the generation of 8-oxoguanine in DNA on the developed nanocomposite material. It was found that the multiplication of microorganisms on the developed nanocomposite material is significantly decreased. At the same time, the nanocomposite does not inhibit proliferation of mammalian cells. The developed nanocomposite material can be used as an affordable and non-toxic nanomaterial to create bacteriostatic coatings that are safe for humans.

Do Iron Oxide Nanoparticles Have Significant Antibacterial Properties?

The use of metal oxide nanoparticles is one of the promising ways for overcoming antibiotic resistance in bacteria. Iron oxide nanoparticles (IONPs) have found wide applications in different fields of biomedicine. Several studies have suggested using the antimicrobial potential of IONPs. Iron is one of the key microelements and plays an important role in the function of living systems of different hierarchies. Iron abundance and its physiological functions bring into question the ability of iron compounds at the same concentrations, on the one hand, to inhibit the microbial growth and, on the other hand, to positively affect mammalian cells. At present, multiple studies have been published that show the antimicrobial effect of IONPs against Gram-negative and Gram-positive bacteria and fungi. Several studies have established that IONPs have a low toxicity to eukaryotic cells. It gives hope that IONPs can be considered potential antimicrobial agents of the new generation that combine antimicrobial action and high biocompatibility with the human body. This review is intended to inform readers about the available data on the antimicrobial properties of IONPs, a range of susceptible bacteria, mechanisms of the antibacterial action, dependence of the antibacterial action of IONPs on the method for synthesis, and the biocompatibility of IONPs with eukaryotic cells and tissues.

Do Iron Oxide Nanoparticles Have Significant Antibacterial Properties?

The use of metal oxide nanoparticles is one of the promising ways for overcoming antibiotic resistance in bacteria. Iron oxide nanoparticles (IONPs) have found wide applications in different fields of biomedicine. Several studies have suggested using the antimicrobial potential of IONPs. Iron is one of the key microelements and plays an important role in the function of living systems of different hierarchies. Iron abundance and its physiological functions bring into question the ability of iron compounds at the same concentrations, on the one hand, to inhibit the microbial growth and, on the other hand, to positively affect mammalian cells. At present, multiple studies have been published that show the antimicrobial effect of IONPs against Gram-negative and Gram-positive bacteria and fungi. Several studies have established that IONPs have a low toxicity to eukaryotic cells. It gives hope that IONPs can be considered potential antimicrobial agents of the new generation that combine antimicrobial action and high biocompatibility with the human body. This review is intended to inform readers about the available data on the antimicrobial properties of IONPs, a range of susceptible bacteria, mechanisms of the antibacterial action, dependence of the antibacterial action of IONPs on the method for synthesis, and the biocompatibility of IONPs with eukaryotic cells and tissues.

[The study of biological effects of different geographical origin goji berries in rats with alimentary hypercholesterolemia]

Food and medicinal plants as well as its' fruits, used in traditional medicine, are now widely used as sources of bioactive phytochemical compounds to impart functional properties to products. Due to the significant variation in phytonutrient content depending on geoclimatic conditions, a comparative study of goji berries collected in different regions seems to be relevant. The aim - comparative study of L. barbarum and L. chinense berries and its biological effects when inclusion in the diet of rats with experimental hyperlipidemia.

MATERIAL AND METHODS

In the berries of L. barbarum (China) and L. chinense (Kazakhstan), the composition of monosaccharides, the content of vitamins (D, E, C), minerals (Mg, Ca, Se), phenolic compounds and steroid substances as well as catalase and superoxide dismutase activity and total antioxidant activity was determined. Biological experiment lasted 186 days, it was carried out on Wistar rats, divided into intact (n=10) and experimental animals (n=48), in which alimentary hyperlipidemia was reproduced for 100 days (diet containing animal fats 5.0-19.0% and cholesterol 0.5-2.0%), further animals were divided in control rats with hyperlipidemia, consuming a standard diet (group 1) and experimental rats, which were supplemented for 86 days with L. barbarum (group 2) and L. chinense (group 3) in an amount of 20% of the diet carbohydrate component. On the 128th and 186th days of the experiment, rats' blood serum was analyzed for total protein, albumin, creatinine and urea, triacylglycerides, total cholesterol, high and low density lipoprotein cholesterol, malondialdehyde and the total antioxidant activity of blood serum was measured.

RESULTS AND DISCUSSION

L. chinense berries, which are characterized by a high content of phenolic compounds (20% higher than in L. barbarum berries), when administered to rats with alimentary hyperlipidemia on the 28th day, reduced the concentration of total cholesterol by 44.1% and low-density lipoproteins by 35.8% relative to control animals, on day 86 contributed to an increase in the concentration of high density lipoproteins to 79.6%. The effect of L. barbarum berries, characterized by an increase in high density lipoproteins in rat blood (by 62.3%), may be due to a higher content of vitamins C, E and selenium (35, 11 and 22% more than in L. chinense), the presence of phytosterols and phytostanols, in particular dodecanoic acid.

CONCLUSION

The data obtained indicate a pronounced antioxidant effect of L. barbarum and L. chinense berries and the possibility of their use in the diet to correct lipid metabolism disorders.

[Influence of meat semiprepared foods produced with an addition of water having a reduced deuterium content on the indicators of the laboratory animals with the model of alloxan diabetes]

The paper presents the results of the study on the influence of water with a reduced deuterium content and the meat semi-prepared foods produced with its addition on the indicators of the laboratory animals with the model of alloxan diabetes. The effect of low concentrations of deuterium on the body weight dynamics was shown as well as the manifestation of glucosuria and ketonuria, and clinico-biological indicators of the animal's blood. The experiment was carried out during 42 days on male rats of Wistar stock, which were divided into 4 groups - 2 experimental, control (n=10) and intact (n=6), and consisted of three stages: adaptational, the stage of modeling of alloxan diabetes (a single intraperitoneal injection of alloxan monohydrate - 12 mg/100 g body weight) and dietic therapeutic. The animals of the experimental groups consumed water with a reduced deuterium content and standard vivarium diet or the meat minced semi-prepared products produced with its addition and cooked to culinary readiness. The control group consumed tap water and standard vivarium diet. In animals of the 1st group, which consumed the meat product, glucosuria persisted up to the 28th day (the 11th day after administration of alloxan), ketonuria up to the 34th day (the 17th day after modeling). In rats of the 2nd group, which consumed water with the decreased deuterium content, glucose in urea was not detected already on the 7th day after administration of alloxan, ketones on the 17th day after modeling of the disease, respectively. In animals of the control group, glucosuria and ketonuria persisted up to the end of the experiment. As a result of the investigations, the positive effect of water with a reduced deuterium content and the meat food produced with its use was established. It was manifested in a decrease of glucose level in the urea of the animals from the experimental groups compared to the control group on the 5th day of disease modeling and normalization on the 17th day of modeling. This experimentally demonstrated the possibility to use deuterium-depleted water in a meat product composition intended for nutrition of people with an impairment of carbohydrate metabolism for correction of metabolic processes.

[The effect of water with modified isotope (D/H) composition on the reproductive function and postnatal development in rats]

Reproductive parameters and postnatal progeny development were evaluated in 4 generations of Wistar rats treated with deuterium depleted water (DDW): parental (F0), first (F1), second (F2) and third (F3). The experiment was carried out on 2 groups of animals: experimental group consumed DDW (50 ppm) and control group consumed purified tap water (150 ppm). Experiment was consist of a preparatory stage, the stage of studying the F0, F1, F2 reproductive parameters and F1, F2, F3 postnatal progeny development Reproductive parameters was assessed by F0, F1, F2 fertility index and F1, F2, F3 offspring viability and development. Fertility index was assessed as the male's ability to fertilize females in the percentage of pregnant females/fertilized males to the total number females and males placed together for mating. Offspring maturing were evaluated by pups viability, development of physical and sexual parameters, emotional and locomotors reflexes within the 1st month of life. Group 1 fertility index in F0 females was 100%, in F1 and F2 females - 99%, in males all generations - 89-100%. Group 1 F1, F2 and F3 offspring viability was high. Number of pups in group 1 F2 offspring was higher by 20% than in group 2. Pups of the 1st group F1, F2 and F3 were less intensively gained weight from the 1st to the 21st day of life compared with group 2, the final weight of the animals in group 1 was higher than in group 2 by 4-6% from 25th to 30th days of life. Assessment of physical parameters development as well as emotional and locomotors reflexes formation did not reveal any difference between group 1 and group 2 F1, F2 and F3 offspring. Obtained results confirmed that DDW did not effect on rat fertility, viability and development of offspring.

[Method of determination organic iodine (iodotyrosines) in food]

It is important to control the substances of the synthesis of biologically active supplements, based on organic forms of iodine (iodotyrosines). But it is no less important to control the content of iodotyrosines in foods. The developed method is sensitive and selective and can determine iodotyrosines with a lower limit of detection (1 ppb). Iodotyrosines have been determined by HPLC-MS/MS. The article contains parameters for chromatographic separation of 3-iodo-L-tyrosine and 3.5-diiodo-L-tyrosine and parameters of the electrospray ionization (ESI) mass spectrometry, describes the methodology of sample preparation and solid phase extraction. The article substantiates the use of mass spectrometry as the most sensitive and selective method for determining the organic iodine as compared to HPLC with UV detection. The enzymatic hydrolysis with proteolytic enzymes has been used for sample preparation in iodothyronine analyses. Solid phase extraction was performed using C18 cartridge. For HPLC-MS/MS analysis iodothyronine derivatives were obtained with a mixture of butanol-acetyl chloride. Degree of iodotyrosine extraction from the matrix of the foodstuffs was not less than 85%, the correlation coefficient of the calibration curve in the concentration range of 1-2000 ng/mL was 0.999, reliable determination of iodine content in foods in the range from 10 to 20 000 mcg/kg.

[Influence of deuterium depleted water on the organism of laboratory animals in various functional conditions of nonspecific protective systems]

The influence of deuterium depleted water with the modified isotope composition on an organism of animals is studied in physiological conditions and development of chronic endogenous intoxication of hepatorenal genesis. The influence of this water on isotope composition of plasma and tissues (the liver and kidneys) in laboratory animals is shown. The impact of this water on biochemical indicators (AST, ALT, alkaline phosphatase, creatinine, bilirubin) and dynamics in body weight of laboratory animals within 42 days is established. As a result of studies the possibility of the preventive use of deuterium depleted water for correction of metabolic processes is shown in various conditions of the functional system of the body's detoxification.

[About the human health safety estimation of ractopamine intake together with the food]

The analysis of scientific data including American and European scientific communities concerning use of ractopamine as a growth factor in food animal production and the argumentation of the maximum permitted levels of ractopamine and levels of ractopamine in meat and byproducts (offal) is carried out. The position of the Russian side stated at the Codex Alimentarius commission 35th session that acceptable ractopamine daily intake is insufficiently validated and cannot be used for the determination of maximum permitted levels of ractopamine in meat and byproducts (offal) is confirmed. It is represented that residual ractopamine intake together with food on the levels which are recommended by the Codex Alimentarius commission and by taking into account the levels of animal products consumption in Russian Federation will lead to unacceptable human health risk level that will promote increasing heart diseases and life expectancy reduction. In this connection Russia states against of acceptance of maximum permitted levels of ractopamine in food.