scholarly journals BISTABILITY AND CYTOTOXICITY OF MEDICAL DEVICES BASED ON CROSS-LINKED BIOPOLYMERS

2018 ◽  
Vol 20 (1) ◽  
pp. 79-85
Author(s):  
E. A. Nemets ◽  
A. P. Pankina ◽  
V. A. Surguchenko ◽  
V. I. Sevastianov
Keyword(s):  
Treatment Time ◽  
Weight Ratio ◽  
Farm Animals ◽  
Cross Linking ◽  
Residual Pressure ◽  
Buffer Solution ◽  
Simple Method ◽  
Constant Weight ◽  
Medical Products ◽  
High Level

The increase in biostability of medical products/materials based on proteins and their derivatives, including resorbable 2Dand 3D-matrices for tissue engineering and regenerative medicine is usually achieved by means of cross-linking with glutaraldehyde (GA). One of the serious fl aws of the products stabilized with GA is their cytotoxicity caused by trace amounts of GA which are diffi cult to remove from cross-linked biopolymer matrices, thus the search for chemical and physical methods of cross-linking of such medical products remains essential. Aim:to compare the infl uence of various cross-linking methods on the cytotoxicity of collagen and gelatin samples.Materials and methods.Samples – fi lms with diameter of 30 mm and thickness of ~ 150 μm, – were obtained by irrigation method usingthesolution of scleral collagen (SC) of Type farm animals or with gelatin with the subsequent drying at 37º С until constant weight on air. Samples of porous matrices in shape of tubes of gelatin and polyoxybutirate-co-valerate with the weight ratio 2:1 were obtained by electrospinning. The cytotoxicity of structurally stabilized samples was studied by fi ve methods: 1) dehydrothermal cross-linking with the residual pressure of 10–20 mm Hg and temperature of 120 °С; 2) injection of GA immediately into the biopolymer solution; 3) with GA vapors; 4) with GA vapors with the subsequent incubation in phosphate buffered saline (PBS) with рН = 7.4; 37 °С; 24 h; 5) with GA vapors with the subsequent incubation in 0.1% lysine solution with рН = 7.4; 37 °С; 24 hour in DMEM medium. Cytotoxicity of samples was evaluated according to the requirements of interstate standard GOST ISO 10993-5-2011 on the culture of mice fi broblasts of NIH 3Т3 line using extracts from samples (37 °С; 24 h) and by means of direct contact of samples with these cells.Results.Matrices treated hydrothermally demonstrated complete absence of cytotoxicity. Samples, fi xated in GA solution in the range of concentrations from 0.01 to 1.0% demonstrated a high level of cytotoxicity which does not answer the requirements of GOST ISO 10993-5-2011. Fixation of collagen and gelatin matrices with GA vapors during 48 h infl uences their cytotoxicity minimally but with the treatment time increased to 72 hours cytotoxicity escalates to severe levels. With the subsequent incubation of cytotoxic gelatin samples in PBS the decrease in cytotoxicity to the levels corresponding with the requirements of GOST ISO 10993-5-2011 was observed. For the analogous decrease in cytotoxicity of collagen fi lms treated with GA vapors during more than 48 h an additional incubation in lysine solution was needed.Conclusion.Dehydrothermal cross-linking method is optimal from the view point of absence of cytotoxicity of stabilized biopolymers, however its area of application is limited by the risk of infl uence of high temperatures on the medico-technical properties of the products. Fixation in GA vapors is a universally applicable and a rather simple method of treatment of medical products or biopolymer-based coatings, but it does not resolve the issue of their cytotoxicity at treatment times exceeding 48 h. Rinsing in buffer solution in case of gelatin or treatment with the amino acid (lysine) solution in case of collagen allow to decrease the level of cytotoxicity of products stabilized with GA vapors to the values corresponding with the requirements of GOST ISO 10993-5-2011.

CONNECTION g.307 G > A SNP POLYMORPHISM OF THE ALPHA-FUKOZYLTRASFERAZA 1 GENE WITH ECONOMIC-USEFUL TRAITS IN THE LARGE WHITE PIG BREED

2017 ◽  
Vol 54 ◽  
pp. 134-140
Author(s):  
H. S. Rudoman ◽  
V. M. Balatsky ◽  
V. Y. Nor ◽  
V. O. Vovk
Keyword(s):  
Genetic Structure ◽  
Information Content ◽  
Analysis Of Variance ◽  
Farm Animals ◽  
Daily Weight Gain ◽  
Fixation Index ◽  
Its Sequencing ◽  
Large White ◽  
Stage Of Development ◽  
High Level

One of the top priorities at the present stage of development of pig breeding remains the development of a set of measures aimed at increasing the resistance animals to various diseases, especially – to colibacteriosis .One of the recent and effective approaches to prevent colibacillosis is using markers of selection; it involves pig genotyping by genome locuses. Chosen locuses are associated with animal sensitivity to the disease and selection of the results of genotyping of animals with increased resistance. Due to researches, one of such locuses is alpha-fukozyltrasferаza 1 gene (FUT1). Gene FUT1 is located in chromosome 6. As a result of its sequencing in the swine breeds of Large White and Swedish Landrace, single-nucleotide polymorphism (g.307 G > A SNP) has been detected. AA genotype determines the resistance of animals to colibacteriosis, while AG and GG genotypes are susceptible to this disease. According to the results of previous studies, the positive effect of allele A was determined not only on the resistance of pigs to colibacteriosis, but also on indicators of fattening and meat productivity and on reproductive performance. In Ukraine, the studies of polymorphism FUT1 g.307 G > A SNP were held fragmentedly and only on certain populations of Ukrainian Meat and Large White breed but without establishing its association with the indicators of productivity of pigs. The aim of our work was to study the genetic structure of Ukrainian Large White breeds, type 1 and the establishment of association. g. 307 G > A SNP FUT1 gene with pigs indicators of productivity. For research the 96 samples of hair were used. DNA isolation from samples with biomaterial were carried out using ion exchange resin Chelex-100. Genotyping was performed by PCR-RFLP by method of Jorgensen et al. (2006). Using DNA analysis of this breeds locus FUT1 was determined by genetic structure. Allele frequency of allele G (0,573) and allele A (0,427) was established The distribution of genotype frequencies was not statistically significantly different from the theoretically expected, calculated by the Hardy-Weinberg criterion. Thus, according to the locus of FUT1 g.307 G > A, the breeds investigated are in a state close to the genetic equilibrium. The negative value of the fixation index by the locus FUT1 g.307 G > A indicates an excess of heterozygotes in the population, and hence the lack of targeted selection for this marker. The valuation was performed by calculating the PIC (polymorphic information content) – information content of polymorphism marker. In the analyzed pig herd for this marker, the PIC has an average value (0,367), which indicates the high level of polymorphism of the given locus and is favorable for the possibility of conducting a search for links between individual genotypes and indicators of productivity. To establish the association g.307 G > A SNP FUT1 gene with indicators of animal productivity, a one-way analysis of variance of the experimental data was used. Based on the results of a one-way analysis of variance, a significant effect of the genotypes of the FUT1gene (g.1849 G > C) on the indicator of the average daily weight gain (р ≤ 0,001), the thickness of the bacon at the level of the VI-VII vertebrae (p ≤ 0.01), reaching live weight of 100 kg (р ≤ 0,001) and breeding index of fattening qualities (р ≤ 0,01) was found. The parameter of the influence of the genetic factor on the test feature was 28,54%, 10,4%, 33,4% and 8,8% respectively. According to the investigated indicators of productivity, animals with genotype AA, which determines resistance to colibacteriosis, dominated the animals with genotypes GG and AG. Based on the results of our research and pre-published data, the multiple effect of the g.307 G > A SNP FUT1 gene is observed, which is associated with the indicators of productivity, which again confirms the polygenicity of the quantitative trait loci of farm animals. Taking into account a high level of polymorphism of the investigated gene and reliable associations of genotypes with indicators of productivity found, it can be recommended to carry out breeding of pigs using genetic information of the g.307 G > A SNP gene FUT1.

Preparation of the copper-containing metallogels based on chitosan for biomedical and agricultural applications

2020 ◽  
Vol 1 (8) ◽  
pp. 60-70
Author(s):  
A. A. Vikhrov ◽  
◽  
V. P. Zubov ◽  
S. Yu. Zaytsev ◽  
◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Animal Husbandry ◽  
Chitosan Solution ◽  
Additional Treatment ◽  
Feed Additives ◽  
Farm Animals ◽  
Cross Linking ◽  
Improved Method ◽  
Polymer Complexes ◽  
Promising Alternative

It is well-known, due to the geological features in a number of regions of the Russian Federation, there may be a shortage of certain microelements and other important “nutrients” in animal diets. The main approach to solve this problem is to use special feed additives. At present, preparations based on organic sources, for example, metal-polymer complexes, are considered a promising alternative. The purpose of this study is to develop an improved method for preparation of the copper-containing polysaccharide complexes and to study their most important parameters. Using CuCl2 as an example, it was shown that the formation of chitosan hydrogels is possible without the usage of potentially hazardous cross-linking agents (for example, glutaraldehyde) or polyvalent anions (for example, SO4 2–), which provide non-covalent cross-linking of chitosan due to electrostatic interactions with NH3 + in its composition. It was found that, upon frontal «gelation» of a 2% chitosan solution (MM 400±100 kDa) in acetic acid (1 vol%), the formation of stable metal gels is observed provided that the content of CuCl2 and ethanol in the precipitant solution is more than 40 mg/ml or more than 24 vol.%, respectively (Vchitosan = Vprecipitant). The obtained complexes are stable in aqueous-alcoholic solutions and swell in water up to destruction (pH 5,5). After additional treatment with an aqueous 1,5% ammonia solution, complexes practically do not swell in solutions with ≥ pH 5,5 (at least τ = 6 days) and dissolve at pH ≤ 4,2. Thus, the use of these complexes is able to provide the release of Cu2 + not in the rumen (pH 6,3–7,2), but in the abomasum (pH ~ 3), which can increase the bioavailability of copper. The development of an improved method for obtaining metal-polysaccharide complexes in a gel form that does not contain «ballast» (in terms of nutritional value and physiology of farm animals) anions (for example, SO4 2–) opens up new opportunities for the development of highly effective feed additives for animal husbandry.

scholarly journals Estimation of cell response in fractionation radiotherapy using different methods derived from linear quadratic model

2015 ◽  
Vol 49 (4) ◽  
pp. 347-356 ◽  
Author(s):  
Safoora Nikzad ◽  
Bijan Hashemi ◽  
Golshan Mahmoudi ◽  
Milad Baradaran-Ghahfarokhi
Keyword(s):  
Cell Response ◽  
Treatment Time ◽  
Theoretical Models ◽  
Accurate Method ◽  
Quadratic Model ◽  
Breast Adenocarcinoma ◽  
Linear Quadratic ◽  
Overall Treatment Time ◽  
Simple Method ◽  
Theoretical Methods

Abstract Background. The aim of this study was to use various theoretical methods derived from the Linear Quadratic (LQ) model to calculate the effects of number of subfractions, time intervals between subfractions, dose per subfraction, and overall fraction time on the cells’ survival. Comparison of the results with experimental outcomes of melanoma and breast adenocarcinoma cells was also performed. Finally, the best matched method with experimental outcomes is introduced as the most accurate method in predicting the cell response. Materials and methods. The most widely used theoretical methods in the literature, presented by Keall et al., Brenner, and Mu et al., were used to calculate the cells’ survival following radiotherapy with different treatment schemes. The overall treatment times were ranged from 15 to 240 minutes. To investigate the effects of number of subfractions and dose per subfraction, the cells’ survival after different treatment delivery scenarios were calculated through fixed overall treatment times of 30, 60 and 240 minutes. The experimental tests were done for dose of 4 Gy. The results were compared with those of the theoretical outcomes. Results. The most affective parameter on the cells’ survival was the overall treatment time. However, the number of subfractions per fractions was another effecting parameter in the theoretical models. This parameter showed no significant effect on the cells’ survival in experimental schemes. The variations in number of subfractions per each fraction showed different results on the cells’ survival, calculated by Keall et al. and Brenner methods (P<0.05). Conclusions. Mu et al. method can predict the cells’ survival following fractionation radiotherapy more accurately than the other models. Using Mu et al. method, as an accurate and simple method to predict the cell response after fractionation radiotherapy, is suggested for clinical applications.

Concentration and Detection of Caliciviruses from Food Contact Surfaces

2002 ◽  
Vol 65 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
ANIL TAKU ◽  
BALDEV R. GULATI ◽  
PAUL B. ALLWOOD ◽  
KERRIN PALAZZI ◽  
CRAIG W. HEDBERG ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Food Service ◽  
Contact Period ◽  
Norwalk Virus ◽  
Buffer Solution ◽  
Simple Method ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Elution Method

Outbreaks of human Norwalk virus (NV) and Norwalk-like viruses often originate in food service establishments. No reliable method is available for the detection of these human caliciviruses on food contact surfaces. We describe a simple method for the detection of NV from stainless steel work surfaces using cultivable feline calicivirus (FCV) as a model. Stainless steel surfaces were artificially contaminated with known amounts of FCV, followed by its elution in a buffer solution. Three methods of virus elution were compared. In the first method, moistened cotton swabs or pieces of nylon filter (1MDS) were used to elute the contaminating virus. The second method consisted of flooding the contaminated surface with eluting buffer, allowing it to stay in contact for 15 min, followed by aspiration of the buffer (aspiration method) after a contact period of 15 min. The third method, the scraping-aspiration method, was similar to the aspiration method, except that the surfaces were scraped with a cell scraper before buffer aspiration. Maximum virus recovery (32 to 71%) was obtained with the scraping-aspiration method using 0.05 M glycine buffer at pH 6.5. Two methods (organic flocculation and filter adsorption elution) were compared to reduce the volume of the eluate recovered from larger surfaces. The organic flocculation method gave an average overall recovery of 55% compared to the filter-adsorption-elution method, which yielded an average recovery of only 8%. The newly developed method was validated for the detection of NV by artificial contamination of 929-cm2 stainless steel sheets with NV-positive stool samples and for the detection of the recovered virus by reverse transcription–polymerase chain reaction.

Swelling of PVA/Chitosan/TiO2 Nanofibers Membrane in Different PH

2020 ◽  
Vol 990 ◽  
pp. 220-224
Author(s):  
Ari Dwi Nugraheni ◽  
Diki Purnawati ◽  
Ani Rohmatillah ◽  
Dian Nur Mahardika ◽  
Ahmad Kusumaatmaja
Keyword(s):  
Time Constant ◽  
Weight Ratio ◽  
Low Ph ◽  
Membrane Stability ◽  
Swelling Behavior ◽  
Cross Linking ◽  
High Ph ◽  
Chitosan Concentration ◽  
Nanofiber Membranes ◽  
Water Swelling

The nanofiber PVA/chitosan have been successfully fabricated by the addition of TiO2 or without TiO2. Nanofiber membranes of PVA/chitosan/TiO2 were fabricated with weight ratio of PVA/chitosan (w/w) 90/10, 85/15, and 80/20. Glutaraldehyde cross-linking was added to increase membrane stability in water. Swelling behavior was tested in three different pH to investigate the swelling behavior of nanofiber membranes of PVA/chitosan with and without TiO2. The result indicated that the addition of chitosan concentration would decrease the swelling index, and increase the time constant (τ). The swelling index will increase in high pH (pH 10.01) compare to low pH (pH 4.01).

scholarly journals Low-Temperature Plasma Modification of Styrene–Butadiene Block Copolymer Surfaces for Improved Adhesion—A Kinetic Approach

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 935 ◽  
Author(s):  
Jacek Tyczkowski ◽  
Hanna Kierzkowska-Pawlak ◽  
Jan Sielski ◽  
Iwona Krawczyk-Kłys
Keyword(s):  
Block Copolymer ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Peel Strength ◽  
Cross Linking ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Plasma Treatment Time ◽  
Styrene Butadiene

This paper proposed a kinetic model that can describe the changes in the adhesion properties of styrene–butadiene (SBS) block copolymer surfaces under the influence of low-temperature plasma treatment. As a measure of these changes, the peel strength of joints formed between the copolymer surface and the polyurethane adhesive was chosen. Five types of low-temperature low-pressure RF plasma, two inert plasmas (Ar and He), and three reactive plasmas (O2, CO2, and CCl4) were tested. It was found that for all these types of plasma, the peel strength with the plasma treatment time first increases rapidly reaching a maximum value, and then there is a visible decrease in peel strength, after which the peel strength increases again. This dependence of the peel strength on the plasma treatment time is very well described by the proposed model, which considers three processes: (1) the generation of radical states followed by the creation of functional groups involved in the adhesive bonding process, (2) the surface cross-linking that decreases the concentration of these functional groups, and (3) the formation of nano-roughness. The model analysis revealed differences between the action of reactive and inert plasmas in the SBS surface cross-linking mechanism and preferential etching process, as well as differences in the generation of radical states between the O2 plasma (electron process) and other plasmas tested (ionic processes).

The Preparation and Characteristics on Chitosan Nano-Carrier with Different Concentration of TPP

2011 ◽  
Vol 197-198 ◽  
pp. 242-245
Author(s):  
Chih Wei Chou ◽  
Hui Hsuan Hsieh ◽  
Te Hsing Wu
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Electron Micrographs ◽  
Strong Interaction ◽  
Weight Ratio ◽  
Cross Linking ◽  
Zeta Potentials ◽  
Transmission Electron ◽  
Polyelectrolyte Complexation ◽  
Polymer Ratio

In this Study, the Tripolyphosphate-Chitosan (TPP-CS) Nano-Carrier was Prepared by Polyelectrolyte Complexation. TPP and CKGM are Polyanion, and can Interact with Cationic Chitosan by Electrostatic Forces. the Nanoparticles Size was Analyzed by the Transmission Electron Micrographs (TEM) and Scattering Electron Micrographs (SEM). FTIR Confirmed Tripolyphosphoric Groups of TPP and CKGM Linked with Ammonium Groups of Chitosan in the Nanoparticles. the CS Nps were Loaded with the Anticancer Drug, Berberine, by Different Concentration of Cross-Linking Agent. the Zeta Potentials of CKGM and CS were Shown as a Function of Ph. it was Observed that CS has Strong Interaction with CKGM about Ph 5.5. the CKGM-CS Nanoparticles were Formed by Mixed Different Weight Ratio of CS and CKGM. the Morphology of CKGM-CS was Characterized by FESEM. the Size of CKGM-CS Particles was Smaller than 150 Nm. the Zeta Potential of CKGM-CS Particles was Proved that the Polymer Ratio can Control the Charge Density.

Effect of Allyl Isothiocyanate against Anisakis Larvae during the Anchovy Marinating Process

2015 ◽  
Vol 78 (4) ◽  
pp. 767-771 ◽  
Author(s):  
FILIPPO GIARRATANA ◽  
FELICE PANEBIANCO ◽  
DANIELE MUSCOLINO ◽  
CHIARA BENINATI ◽  
GRAZIELLA ZIINO ◽  
...  
Keyword(s):  
Phosphate Buffer Solution ◽  
Allyl Isothiocyanate ◽  
Significant Activity ◽  
Liquid Media ◽  
Buffer Solution ◽  
The Family ◽  
High Level ◽  
Strong Antimicrobial Activity ◽  
Potential Use

Allyl isothiocyanate (AITC), is a natural compound found in plants belonging to the family Cruciferae and has strong antimicrobial activity and a biocidal activity against plants parasites. Anisakidosis is a zoonotic disease caused by the ingestion of larval nematodes in raw, almost raw, and marinated and/or salted seafood dishes. The aim of this work was to evaluate the effect of AITC against Anisakis larvae and to study its potential use during the marinating process. The effects of AITC against Anisakis larvae were tested in three experiment: in vitro with three liquid media, in semisolid media with a homogenate of anchovy muscle, and in a simulation of two kinds of anchovy fillets marinating processes. For all tests, the concentrations of AITC were 0, 0.01, 0.05, and 0.1%. Significant activity of AITC against Anisakis larvae was observed in liquid media, whereas in the semisolid media, AITC was effective only at higher concentrations. In anchovy fillets, prior treatment in phosphate buffer solution (1.5% NaCl, pH 6.8) with 0.1% AITC and then marination under standard conditions resulted in a high level of larval inactivation. AITC is a good candidate for further investigation as a biocidal agent against Anisakis larvae during the industrial marinating process.

scholarly journals Assessment of Shiga Toxin-Producing Escherichia coli Isolates from Wildlife Meat as Potential Pathogens for Humans

2009 ◽  
Vol 75 (20) ◽  
pp. 6462-6470 ◽  
Author(s):  
Angelika Miko ◽  
Karin Pries ◽  
Sabine Haby ◽  
Katja Steege ◽  
Nadine Albrecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Farm Animals ◽  
Clonal Lineage ◽  
E Coli ◽  
Virulence Markers ◽  
Potential Source ◽  
Human Illness ◽  
High Level ◽  
Game Animals

ABSTRACT A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx 2, stx 2d, and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains.

scholarly journals Comparison of DNA extraction methods for Aspergillus fumigatus using real-time PCR

2006 ◽  
Vol 55 (9) ◽  
pp. 1187-1191 ◽  
Author(s):  
Lisa J. Griffiths ◽  
Martin Anyim ◽  
Sarah R. Doffman ◽  
Mark Wilks ◽  
Michael R. Millar ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Extraction ◽  
Real Time Pcr ◽  
Diagnostic Technique ◽  
Extraction Methods ◽  
Simple Method ◽  
Bead Beating ◽  
Fungal Dna ◽  
Dna Extraction Methods ◽  
High Level

Newer methods such as PCR are being investigated in order to improve the diagnosis of invasive aspergillosis. One of the major obstacles to using PCR to diagnose aspergillosis is a reliable, simple method for extraction of the fungal DNA. The presence of a complex, sturdy cell wall that is resistant to lysis impairs extraction of the DNA by conventional methods employed for bacteria. Numerous fungal DNA extraction protocols have been described in the literature. However, these methods are time-consuming, require a high level of skill and may not be suitable for use as a routine diagnostic technique. Here, a number of extraction methods were compared: a freeze–thaw method, a freeze–boil method, enzyme extraction and a bead-beating method using Mini-BeadBeater-8. The quality and quantity of the DNA extracted was compared using real-time PCR. It was found that the use of a bead-beating method followed by extraction with AL buffer (Qiagen) was the most successful extraction technique, giving the greatest yield of DNA, and was also the least time-consuming method assessed.

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