Adsorption of cationized xylans onto polyethylene terephthalate fabrics for antimicrobial medical textiles

2017 ◽  
Vol 89 (4) ◽  
pp. 473-486 ◽  
Author(s):  
Nena Velkova ◽  
Lidija Fras Zemljic ◽  
Bodo Saake ◽  
Simona Strnad

The main aim of this research was development of thin functional xylan layers on polyethylene terephthalate (PET) fabric surfaces. Xylans, derived from hard wood and oat spelt, were modified chemically in order to introduce cationic functional groups. Cationization of xylans was proved by elemental analysis, total bound nitrogen determination, and Raman techniques, as well as by polyelectrolyte titrations. The antimicrobial activity of xylans was investigated by the determination of Minimal Inhibitory Concentration against bacteria S. aureus and E. coli, and fungi C. albicans. Xylan solutions were then applied onto PET fabric using the spray coating technique. Charging behavior of the treated PET fabric samples was evaluated by potentiometric titration supported by X-ray electron spectroscopy. Hydrophilicity was examined by the water contact angle determination. The morphology of coated fabrics was analyzed using Scanning Electron Microscopy. The results of microbial testing showed that PET fabrics functionalized by cationic xylans act antimicrobially against S. aureus and E. coli. The presented work suggests that cationized xylans, originally derived from hard wood and/or oat spelt, could be applied successfully as a coating material for PET fabrics in order to introduce hydrophilicity and antimicrobial properties.

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1991
Author(s):  
Rossella Bengalli ◽  
Luisa Fiandra ◽  
Claudia Vineis ◽  
Diego Omar Sanchez-Ramirez ◽  
Nuno G. Azoia ◽  
...  

Polypyrrole (PPy) nanoparticles (NPs) are used for the coating of materials, such as textiles, with biomedical applications, including wound care and tissue engineering, but they are also promising antibacterial agents. In this work, PPy NPs were used for the spray-coating of textiles with antimicrobial properties. The functional properties of the materials were verified, and their safety was evaluated. Two main exposure scenarios for humans were identified: inhalation of PPy NPs during spray (manufacturing) and direct skin contact with NPs-coated fabrics (use). Thus, the toxicity properties of PPy NPs and PPy-coated textiles were assessed by using in vitro models representative of the lung and the skin. The results from the materials’ characterization showed the stability of both the PPy NP suspension and the textile coating, even after washing cycles and extraction in artificial sweat. Data from an in vitro model of the air–blood barrier showed the low toxicity of these NPs, with no alteration of cell viability and functionality observed. The skin toxicity of PPy NPs and the coated textiles was assessed on a reconstructed human epidermis model following OECD 431 and 439 guidelines. PPy NPs proved to be non-corrosive at the tested conditions, as well as non-irritant after extraction in artificial sweat at two different pH conditions. The obtained data suggest that PPy NPs are safe NMs in applications for textile coating.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 100 ◽  
Author(s):  
Shamik Chaudhuri ◽  
Chang-Mou Wu

In this study, we synthesized a random poly[(N-isopropylacrylamide)-co-(2-hydroxyethylmethacrylate)-co-(N-methylolacrylamide)] [poly(NIPAAm-co-HEMA-co-NMA)] copolymer through free-radical polymerization. The NIPAAm, HEMA and NMA moieties were framed to provide thermoresponsiveness, water absorption and retention control, and chemical cross-linking to achieve stability in aqueous medium, respectively. The copolymer showed a significant change in optical transmittance with a variation in temperature due to the change in volume (i.e., hydrophilic/hydrophobic) between 25 °C and 40 °C, attributed to the lower critical solution temperature property of the NIPAAm moiety. The copolymers were wire-bar-coated onto polyethylene terephthalate (PET) fabric. Variation in the water contact angle affirmed the switchable wettability due to the change in temperature. We tested the coated fabrics for moisture absorption and release at different temperatures. The results at 20 °C and 37 °C indicated that the P2 copolymer had the highest moisture absorption and release capability. Therefore, the copolymers with tailored properties can be used as smart textiles for activity specific clothing.


2021 ◽  
pp. 004051752199090
Author(s):  
Eshraga AA Siddig ◽  
Yu Zhang ◽  
Baojing Yang ◽  
Tianshu Wang ◽  
Jianjun Shi ◽  
...  

Commercial dull polyethylene terephthalate (PET) fabric treated by radio frequency (13.56 MHz) plasma and further coated with perfluoroalkyl methacrylate copolymer C6 displays much highly durable hydrophobicity and oleophobicity. The as-prepared fabric exhibited a water contact angle above 170°, a water spray rating of 80 (ISO 3), and oil resistance ratings of B and C separately for different oil composition grades after 10 washing cycles, which were two levels higher than the untreated and C6-coated PET[TiO2] fabric. The organic component PET was more prone to etching than TiO2, which created a waviness structure and exposed prominent TiO2 nanoparticles on the PET fiber surface. The relative atom ratio O and Ti increased through energy-dispersive X-ray spectroscopy spectra and X-ray photoelectron spectroscopy analysis. This result indicates that the exposure of TiO2 and the introduction of reactive polar groups such as O=C-O on the fiber surface contributed to react with C6 and improved the washing durability. In general, such coating technology may provide a simple benign technique for constructing materials with physicochemical properties.


Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Yuling Lai ◽  
Ying Guo ◽  
Liyun Xu ◽  
Xijiang Chang ◽  
Xingqun Zhang ◽  
...  

Superhydrophobic antibacterial fabric possesses properties of antibacterial and antibacterial adhesion and shows huge demand in the field of medical textiles. However, current technologies are unable to fully address this. Hence, a simple method is highly desirable. Herein, the pristine polyester (PET) fabric is immersed into the solution containing ZnO nanoparticle and polydimethylsiloxane (PDMS), and the fiber surfaces are uniformly covered by a ZnO-PDMS layer after being treated by low pressure Ar plasma. The weight gain rate of the treated fabric is 3.5%, which is basically unchanged, and the air permeability, moisture permeability, and tensile properties of the fabric are basically not affected. It is found that the water contact angle (WCA) of the fabric is over 162.7°and sliding angle (SA) is less than 10°. The stable binding of PDMS and PET fibers induces a robust superhydrophobicity; even after 300 washing cycles and 600 friction cycles, it still remains superhydrophobic. The antibacterial rates of Escherichia coli and Staphylococcus aureus before washing were 99.89% and 99.85%, respectively, and after 100 cycles of washing, the antibacterial rates decreased to 99.36% and 99.17%, respectively. Therefore, it shows a good development prospect in the application of protecting clothing or textiles that require good antibacterial properties (such as bed sheets, duvet covers, etc.).


Author(s):  
R. Shahanenko ◽  
N. Ilnitskiy ◽  
V. Shahanenko ◽  
S. Rublenko

Development of antibiotic-resistant strains of microorganisms is a dangerous phenomenon, actively progressing every year. The uncontrolled use of antibiotics for animals, accumulation in products of animal origin ultimately poses a danger to human health. That is why a decrease in the use of antibiotics and searching alternatives of antibiotic is acute and relevant issues. Therefore, the aim of our research was to study the antimicrobial properties of ozone in relation to pathogens of purulent infection and to show the possibility of using ozone therapy as a potential method of antimicrobial therapy for animals. The materials for determining antimicrobial effect of ozone was 12 samples of purulent exudate in an amount of 2 ml, taken from dogs with purulent wounds before and after sanitation by ozonized 0.87% NaCl solution. Complexity course of wound process with purulent inflammation largely depends on from degree of microbial contamination of the wound and species composition of microorganisms. Therefore, an important aspect in our research was the study of the antimicrobial properties of ozone on its action of purulent exudate «in vitro» and «in vivo» and the determination of the bactericidal effect on microorganisms. The most stable and informative indicator of assessing nature of purulent-inflammatory process is the determination of total number of microorganisms in 1 ml of discharge from a purulent wound. The total microbial number was determined by the method of serial dilutions according to Pasteur. Serial ten-fold dilutions from 10-1 to 10-9 were prepared from purulent exudate in test tubes with sterile MPB (9 ml each). Species composition of microorganisms was determined by cultural and biochemical properties of cultivated microbial colonies, followed microscopy of smears from pure cultures stained using method of Gram. Samples of purulent exudate were subjected to microbiological examination before treatment, and after 30 minutes of washing by ozonized isotonic solution NaCl (ozone concentration of 7 mg/ml). A microbiological study of purulent exudate was also carried out, pre-treated with ozone at a concentration of 7 mg/ml «in vitro» in a test tube in an amount of 2 ml by passing it through exudate (sparging) at a flow rate of 0.5 L/min and a processing time of 10 min. Samples were examined immediately after sampling and sparging. "Microbial landscapes" of purulent wounds were presented by associations of Staph. aureus, Str. faecalis, E. coli. Microbial seeding of purulent exudate for treatment ranged from 6.6 • 10-10 to 3.7 • 10-8 CFU/ml, however, after 10 min of bubbling «in vitro» at an ozone concentration of 7 mg/ml, the degree of microbial seeding of samples did not exceed 10-4 CFU/ml and ranged from 3.1 • 10-4 to 2.3• 10-3 CFU/ml. As shown by the results of microbiological studies, the growth of microorganisms on a nutrient medium in bacteriological plates with purulent exudate samples treated with ozone with concentration of 7 mg/ml was already absent at 10-5 degrees of dilution, which indicates the pronounced antimicrobial properties of ozone. The study «in vivo»also indicates that even after a single use of an ozonized isotonic NaCl solution at an ozone concentration of 7 mg/ml, it completely prevents the growth of Staph. aureus, Str. faecalis, E. coli. and causes 100% death mentioned associations of microorganisms. The results of microbiological studies are confirmed by clinical data. So, on the third day of treatment, the animals in the lesion zone had a small amount of wound exudate, and the microbial number of the latter was 1.4 • 10-4 − 3.1 • 10-³ CFU/ml, below the critical level of contamination and in most cases not leads to the progression of a purulent-inflammatory process. Ozone destroys all types of bacteria, viruses, fungi and protozoa. At the same time, ozone at a concentration of 7 mg/ ml does not have an irritating effect on body tissues, therefore, ozone therapy can be considered as an additional or alternative therapy of bacterial infection. Key words: ozone, ozonetherapy, purulent wounds, antibiotic resistance.


Author(s):  
M. Haider ◽  
B. Bohrmann

The technique of Z-contrast in STEM offers the possibility to determine the local concentration of macromolecules like lipids, proteins or DNA. Contrast formation depends on the atomic composition of the particular structure. In the case of DNA, its phosphorous content discriminates it from other biological macromolecules. In our studies, sections of E. coli, the dinoflagellate Amphidinium carterae and Euglena spec. cells were used which were obtained by cryofixation followed by freeze-substitution into acetone with 3% glutaraldehyde. The samples were then embedded either in Lowicryl HM20 at low temperature or in Epon at high temperature. Sections were coated on both sides with 30Å carbon.The DF- and the inelastic image have been recorded simultaneously with a Cryo-STEM. This Cryo-STEM is equipped with a highly dispersive Electron Energy Loss Spectrometer. With this instrument pure Z-contrast can be achieved either with a Filtered DF-image divided by the inelastic image or, as is used in this paper, by dividing the conventional DF-image by an inelastic image which has been recorded with an inelastic detector whose response is dependent on the total energy loss of the inelastically scattered electrons.


2018 ◽  
Vol 40 (4) ◽  
Author(s):  
Dang Thi Ngoc Ha ◽  
Le Thi Thu Hong ◽  
Truong Nam Hai

Single chain variable fragments (scFv) have widely been used in research, diagnosis and treatment, but the scFv is considered as difficult protein for expression in E. coli. In previous studies, we expressed a construction of recombinant single chain variable fragments again antigen specific for blood type A (antiA-scFv) individually or fused with Trx or SUMO. However, soluble fraction was low abandant and only approximately 40% when fused with Trx, the other cases were expressed in form of inclusion body. Therefore, it was difficult for purification, refolding and activity assesment. In thispaper, we demonstrated a suitable construction for soluble production of antiA-scFv fused with SUMO (SM/antiA-scFv) in presence of chaparones. Under fermentation with 0.1 mM IPTG at 20oC, the SM/antiA-scFv was entirely expressed in soluble form. Importantly, after cleavage from SUMO with SUMOprotease, antiA-scFv was still maintained in the supernatant fraction. Therefore, it can help ensure bioactivity and is useful for purification process. To the best of our knowledge, this is the first report showing soluble recombinant scFv fused with SUMO in presence of chaperone for determination of blood group antigens. Thus, this result facilitates the optimal study of soluble expression, purification and bioactivity determination of the antiA-scFv recombinant antibody. 


2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


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