Anti-adhesion Ability Research Articles

Chromium Cross-Linking Based Immobilization of Silver Nanoparticle Coating on Leather Surface with Broad-Spectrum Antimicrobial Activity and Durability.

Leather with durable and broad-spectrum antimicrobial properties is very attractive in applications to produce diabetic shoes. In this work, gallic acid stabilized silver nanoparticles (GA@AgNPs) were prepared as water-borne finishing agent to be spray-coated on leather surface, with subsequent immobilization onto skin collagen via chromium(III) cross-linking. Such chemical anchoring of AgNPs onto microscaled collagen fibers not only enhanced the hydrophobicity of leather surface but also converted the surface ζ-potential from a positive charge to a negative charge, resulting in the excellent microbial antiadhesive ability of GA@AgNP-coated leather because of its dual-hydrophobic and electrostatic repelling of microbial adhesion. Such GA@AgNP coating also exhibited broad-spectrum antimicrobial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus, and Candida albicans, with killing efficiencies all higher than 99%. Moreover, the killed microbes could be easily released from this anionic GA@AgNP spray coating by simply washing, preserving, and giving long-term antimicrobial activity to leather products. Most of all, the robust immobilization of AgNPs guaranteed the durably antimicrobial activity of such GA@AgNP-coated leather against laundry, perspiration, and mechanical abrasion in real daily use.

Justification of antiadhesive components choice for the composition of effervescent tablets with thick extract of betula verrucosa leaves

Urolithiasis and inflammatory diseases of the urinary system are of great importance in recent times. Only urolithiasis affects about 15 % of the population. Therefore, the development of new domestic drugs for the treatment of urinary system disorders is an urgent task. In the pharmaceutical market of Ukraine, there are medicinal products of plant origin that exhibit antispasmodic, antiseptic, anti-inflammatory, diuretic effects, as well as dissolve concrements and eliminate them from urine. Aim of the work. To determine the optimal composition of antiadhesive components for the production of effervescent tablets with a thick extract of silver birch leaves. Materials and methods. During the experiment, the effects of macrogol 6000, macrogol 4000, glycine and fumaric acid on the technological characteristics of the model granulates and the resulting tablets were investigated. In the experiments, modern equipment and techniques were used to study tablets ejection force, granules fluidity, strength of tablets, disintegration of tablets. Results. Macrogols of 4000 and 6000 showed the best results in all studies. With satisfactory flow rates, they showed a high anti-adhesive ability and the resulting tablets had the highest rates of crushing resistance. Macrogol 4000 has the most optimal anti-adhesive properties, while the most intense reduction in the pressure of pushing tablets from the matrix is observed at its content under 4 %. Macrogol 6000 has satisfactory lubricating properties, but at a concentration of 6 %. Thus, based on the performed studies, it has been found that for the production of effervescent tablets with a thick extract of silver birch leaves it is advisable to use the macrogol 4000 (or macrogol 6000) as the antiadhesive component. Conclusions. Hydrophilic lubricants (macrogols 4000 and 6000, glycine, fumaric acid) were used to determine the optimal composition of anti-adhesive excipients to produce effervescent tablets with a thick extract of silver birch leaves, among which the best results for all were shown by macrogols 4000 and 6000. According to the results of the research, as the antiadhesive component for the preparation of tablets with thick extract of silver birch leaves, macrogol 4000 was selected which showed high antiadhesive ability and the obtained tablets had the highest indices for resistance to crushing, while the most intense reduction of the pressure of pushing out tablets from the matrix was observed at macrogol 4000 concentration up to 4 % in tablet mass.

Action of Monomeric/Gemini Surfactants on Free Cells and Biofilm of Asaia lannensis.

We investigated the biological activity of surfactants based on quaternary ammonium compounds: gemini surfactant hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) (C6), synthesized by the reaction of N,N-dimethyl-N-dodecylamine with 1,6-dibromohexane, and its monomeric analogue dodecyltrimethylammonium bromide (DTAB). The experiments were performed with bacteria Asaia lannensis, a common spoilage in the beverage industry. The minimal inhibitory concentration (MIC) values were determined using the tube standard two-fold dilution method. The growth and adhesive properties of bacterial cells were studied in different culture media, and the cell viability was evaluated using plate count method. Both of the surfactants were effective against the bacterial strain, but the MIC of gemini compound was significantly lower. Both C6 and DTAB exhibited anti-adhesive abilities. Treatment with surfactants at or below MIC value decreased the number of bacterial cells that were able to form biofilm, however, the gemini surfactant was more effective. The used surfactants were also found to be able to eradicate mature biofilms. After 4 h of treatment with C6 surfactant at concentration 10 MIC, the number of bacterial cells was reduced by 91.8%. The results of this study suggest that the antibacterial activity of the gemini compound could make it an effective microbiocide against the spoilage bacteria Asaia sp. in both planktonic and biofilm stages.

Quantitative assessment of interfacial forces between two rough surfaces and its implications for anti-adhesion membrane fabrication

Abstract The super anti-adhesion ability of lotus leaf inspires to fabricate anti-adhesion membranes. To achieve this goal, a novel approach to quantify the interfacial forces between a randomly rough particle and membranes with special surface morphology, was developed. In this study, the rough surfaces of foulant particle and membrane were firstly modeled by the modified two-variable Weierstrass-Mandelbrot (WM) function and a rigorous mathematical function, respectively. Thereafter, quantification approach based on the combination of surface element integration (SEI) method and composite Simpson’s rule was deduced. This approach was verified to be feasible to quantify the interfacial forces between a rough particle and a rough flat surface. By using this novel approach, effects of scaled amplitude and water contact angle of membrane surface on interfacial forces were investigated. It was found that, the attractive forces between foulants and membrane surface would rather weaker or even become repulsive with increase in size of asperities and surface hydrophilicity, well explaining the phenomenon regarding the super anti-adhesion ability of lotus leaf. This study gives important implications for fabrication of anti-adhesion membranes.

Surface modification of silicon wafer by grafting zwitterionic polymers to improve its antifouling property

Silicon (111) wafer was modified by triethoxyvinylsilane containing double bond as an intermedium, and then P4VP (polymer 4-vinyl pyridine) brush was “grafted” onto the surface of silicon wafer containing reactive double bonds by adopting the “grafting from” way and Si-P4VP substrate (silicon wafer grafted by P4VP) was obtained. Finally, P4VP brush of Si-P4VP substrate was modified by 1,3-propanesulfonate fully to obtain P4VP-psl brush (zwitterionic polypyridinium salt) and the functional Si-P4VP-psl substrate (silicon wafer grafted by zwitterionic polypyridinium salt based on polymer 4-vinyl pyridine) was obtained successfully. The antifouling property of the silicon wafer, the Si-P4VP substrate and the Si-P4VP-psl substrate was investigated by using bovine serum albumin, mononuclear macrophages (RAW 264.7) and Escherichia coli (E. coli) ATTC25922 as model bacterium. The results showed that compared with the blank sample-silicon wafer, the Si-P4VP-psl substrate had excellent anti-adhesion ability against bovine serum albumin, cells and bacterium, due to zwitterionic P4VP-psl brush (polymer 4-vinyl pyridine salt) having special functionality like antifouling ability on biomaterial field.

Tuning anti-adhesion ability of membrane for a membrane bioreactor by thermodynamic analysis

Developing strategies that allow tuning anti-adhesion ability of membranes in membrane bioreactors (MBRs) is of primary interest in membrane fouling research. In this study, interaction energies between foulants and membrane in three different interaction scenarios were systematically assessed based on thermodynamic methods. It was found that, membrane surface electron donor tension (γ−) rather than surface hydrophilicity was a more reliable indicator to predict adsorptive fouling. The interaction energy would be continuously repulsive in the initial range of separation distance when membrane γ− is higher than a critical value, suggesting that designing membrane with γ− higher than a critical value would confer membrane with high anti-adhesion ability. It was also found that, zeta potential on the membrane surface exerted certain effects on adsorptive fouling. This study proposed a novel strategy regarding adjusting membrane γ− to tune anti-adhesion ability of membrane, and also offered a thermodynamic theoretical background to this strategy.

Antagonistics against pathogenic Bacillus cereus in milk fermentation by Lactobacillus plantarum ZDY2013 and its anti-adhesion effect on Caco-2 cells against pathogens

Lactobacillus plantarum ZDY2013 is a potential probiotic isolated from fermented bean acid. In this study, we aimed to evaluate the in vitro antimicrobial activity of this organism against Bacillus cereus in milk fermentation, the antiadhesion ability on intestinal epithelial cells, as well as its ability to abrogate the cytotoxic effect and expression levels of genes. We found no antimicrobial activity produced by L. plantarum once the pH was adjusted to 6.0 and 7.0. The pH decreased continuously when L. plantarum and B. cereus were co-incubated during milk fermentation, which caused a decrease in the B. cereus counts. Antiadhesion assays showed that L. plantarum can significantly inhibit the adhesion of enterotoxin-producing B. cereus ATCC14579 and pathogenic B. cereus HN001 by inhibition, competition, and displacement. The supernatants of B. cereus, either alone or in conjunction with L. plantarum, caused damage to the membrane integrity of Caco-2 cells to release lactate dehydrogenase. In addition, L. plantarum tended to attenuate proinflammatory cytokine and oxidative stress gene expression on Caco-2 cells, inducing with B. cereus HN001 supernatants. This study provided systematic insights into the antagonistic effect of L. plantarum ZDY2013, and the information may be helpful to explore potential control measures for preventing food poisoning by lactic acid bacteria.

Postoperative anti-adhesion ability of a novel carboxymethyl chitosan from silkworm pupa in a rat cecal abrasion model

N,O-Carboxymethyl chitosan (NOCC) can prevent postsurgical adhesion formation. Here, we described the preparation of a novel silkworm pupa NOCC and its effects on the prevention of postoperative adhesion in a rat cecal abrasion model. The degree of deacetylation (DDA) of silkworm pupa chitosan was only 49.87±0.86%; regardless, it was used as the raw material to construct the novel silkworm pupa NOCC, which had a weaker crystallinity than the NOCC standard. Sixty male Sprague–Dawley rats were divided into three groups and treated as follows: 0.9% normal saline solution as a negative control, medical anti-adhesion gel as a positive control and the silkworm pupa NOCC anti-adhesion solution. Two and three weeks after surgery, the animals were killed and the adhesion formation was scored. The silkworm pupa NOCC solution significantly decreased the levels of WBC, TNF-α, IL-1β, IL-2, IL-6 and IL-8 but had no effect on IL-4. Additionally, a lower level of TGF-β1 expression was found in the silkworm pupa NOCC group, and significantly less collagen (P<0.01) and fewer inflammatory cells and fibroblasts were detected in the animals of this group. These results suggested that the novel NOCC from silkworm pupa using the method described here have potential applications in the prevention of postoperative intestinal adhesion.

Fabrication and anti-biofouling properties of alumina and zeolite nanoparticle embedded ultrafiltration membranes

Nanoparticle embedded polysulfone ultrafiltration (UF) membranes were prepared by using the in situ embedment method, and the anti-biofouling properties of the prepared membranes were evaluated by conducting bacteria adhesion test, bacterium inactivation test and biofilm formation test separately. Among the several aluminum and/or silicon oxide nanoparticles tested, alumina (Al2O3) and Linda type L (LTL) zeolite nanoparticles were successfully embedded which could be evenly dispersed on membrane surface with high coverage ratio (38% and 49%, respectively) and were resistant to hydraulic shear detachment. The water contact angles for the nanoparticle embedded membranes (UF-Al2O3 and UF-LTL) and the control membrane (UF-C) were 57°, 40° and 66°, respectively. Owing to the higher surface hydrophilicity, both UF-Al2O3 and UF-LTL demonstrated a higher filterability than UF-C. Biofouling was inhibited on both UF-Al2O3 and UF-LTL, indicated by the lower Pseudomonas aeruginosa biofilm formation rate. Further investigation showed that both UF-Al2O3 and UF-LTL exhibited a high anti-adhesion efficiency to both Escherichia coli and P. aeruginosa, but no bacteriocidal effect on E. coli. The anti-biofouling ability of UF-Al2O3 and UF-LTL mainly benefited from the anti-adhesion ability attributed to the embedded nanoparticles. The improved anti-adhesion ability could not be simply explained by the enhanced hydrophilicity.

Method for Determining of the Anti-adhesion Ability of Cutting Fluids

Method for Determining of the Anti-adhesion Ability of Cutting Fluids

Effects of La&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; on Microstructure and Wear Properties of Thermal Clad NiCoW/ La&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Composite Coatings

NiCoW alloy powders with and without 0. 4 % La2O3were flame spray welded onto 1045 carbon steel substrate. Vickers microhardness profiles of the coatings were carried out. Sliding wear tests in dry conditions were carried out by means of weight-loss method for several applications in oil industries. For this purpose, Ni-based alloy and high chrome cast iron were used as compared materials. A scanning electron microscope (SEM) was used to analyze the wear phenomena of samples. The result showed that the hardness of the coatings can be improved by addition of 0. 4 % La2O3, and the anti-adhesion, anti-scratching, and plastic deformation resistance abilities of coatings are increased with the addition of La2O3.

Preparation, Characterization and Uptake of PEG-Coated, Muco-Inert Nanoparticles in HGC-27 Cells, a Mucin-Producing, Gastric-Cancer Cell Line

To prepare polyethylene glycol (PEG)-coated, muco-inert nanoparticles, we investigated the interaction between nanoparticles and mucin, and analyzed the cellular uptake of nanoparticles in HGC-27 cells, which are a mucin-producing, gastric cancer cell line. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were manufactured through a nanoprecipitation/emulsion evaporation technique, and coumarin-6 was encapsulated as a fluorescent marker. We characterized and evaluated the nanoparticles. We examined the cellular uptake of PLGA nanoparticles in HGC-27 cells with confocal laser scanning microscopy and flow cytometry. Nanoparticles prepared using a nanoprecipitation method were 120-150 nm in size, while nanoparticles prepared using an emulsion evaporation method were 400-450 nm in size. EE% of coumarin-6 in the nanoparticles was more than 80%. The anti-adhesive ability of nanoparticles to pig-gastric mucin (PM) was notably affected by PEG coating-density, 10% PEG2000-PLGA nanoparticles and 15% PEG2000-PLGA nanoparticles possessed the strongest resistance to PM. However, the PLGA nanoparticles were strong while the chitosan-loaded nanoparticles were very weak. Our results from both confocal laser scanning microscopy as well as flow cytometry showed that mPEG-PLGA-NPs are rapidly uptaken by mucin-producing HGC-27 cells. The number of 10% mPEG-PLGA-NPs taken up by cells was 1.6- to 2.1-fold higher than PLGA-NPs incubated for the same amount of time. In conclusion, mPEG-PLGA-NPs possess hydrophilic and near-neutrally-charged surfaces that minimize mucoadhesion by reducing hydrophobic or electrostatic interactions. Both the low-PEG MW and the high density of PEG surface coverage are critical for the uptake of mPEG-PLGA-NPs in HGC-27 cells. At the same time, the size of nanoparticles was also very important.

Wear Behaviour of Thermal Spray Welded FeNi and CeO&lt;sub&gt;2&lt;/sub&gt; Composite Coatings

FeNi alloy powders with and without 0.4 % CeO2 were flame spray welded onto 1045 carbon steel substrate. Vickers microhardness profiles of the coatings were carried out. Sliding wear tests in dry conditions were carried out by means of weight-loss method for several applications in oil industries. For this purpose, Ni-based alloy and high chrome cast iron were used as compared materials. A scanning electron microscope(SEM) was used to analyze the wear phenomena of samples. The result showed that the hardness of the coatings can be improved by addition of 0. 4 % CeO2, and the anti-adhesion, anti-scratching, and plastic deformation resistance abilities of coatings are increased with the addition of CeO2.

Novel pH-sensitive chitosan-based hydrogel for encapsulating poorly water-soluble drugs

Carboxymethyl–hexanoyl chitosan (CHC) is an amphiphilic chitosan derivative with excellent swelling ability and water solubility under natural conditions. In this work, the influence of the degree of carboxymethyl and hexanoyl substitution on the pH-sensitive swelling behavior, drug release behavior, and antiadhesion behavior of CHC hydrogels (cross-linked with genipin) were studied. It was found that the pH sensitivity was more pronounced in CHC than in N,O-carboxymethyl chitosan because the hexanoyl group altered the state of water in CHC by inhibiting intermolecular hydrogen bonding. In addition, greater pH sensitivity was observed in samples bearing longer hydrophobic chains (carboxymethyl–palmityl chitosan). Interestingly, when used with ibuprofen (a poorly water-soluble therapeutic agent used here as a model drug), the bursting release of the drug was less prominent in the CHC samples having a high degree of carboxymethyl substitution. The CHC hydrogel also demonstrated good cell compatibility and its antiadhesive ability after grafting was altered by changes in the degree of hexanoyl substitution.