The Effect of Plasma Pretreatment and Cross-Linking Degree on the Physical and Antimicrobial Properties of Nisin-Coated PVA Films

Stable antimicrobial nisin layers were prepared on the carrying medium-polyvinyl alcohol (PVA) films, crosslinked by glutaric acid. Surface plasma dielectric coplanar surface barrier discharge (DCSBD) modification of polyvinyl alcohol was used to improve the hydrophilic properties and to provide better adhesion of biologically active peptide-nisin to the polymer. The surface modification of films was studied in correlation to their cross-linking degree. Nisin was attached directly from the salt solution of the commercial product. In order to achieve a stable layer, the initial nisin concentration and the following release were investigated using chromatographic methods. The uniformity and stability of the layers was evaluated by means of zeta potential measurements, and for the surface changes of hydrophilic character, the water contact angle measurements were provided. The nisin long-term stability on the PVA films was confirmed by tricine polyacrylamide gel electrophoresis (SDS-PAGE) and by antimicrobial assay. It was found that PVA can serve as a suitable carrying medium for nisin with tunable properties by plasma treatment and crosslinking degree.

Download Full-text

Hydrophilic and antimicrobial properties of acrylic acid and chitosan bigrafted polypropylene melt-blown nonwoven membrane immobilized with silver nanoparticles

Textile Research Journal ◽

10.1177/0040517516676066 ◽

2016 ◽

Vol 88 (2) ◽

pp. 182-190 ◽

Cited By ~ 4

Author(s):

Yuanlin Ren ◽

Jieyun Zhao ◽

Xiuli Wang

Keyword(s):

Acrylic Acid ◽

Photoelectron Spectroscopy ◽

Ag Nanoparticles ◽

Antimicrobial Properties ◽

Water Contact ◽

Angle Measurements ◽

Static Water ◽

Polypropylene Melt ◽

Highly Hydrophobic ◽

Melt Blown Nonwoven

The polypropylene melt-blown nonwoven membrane (PPM) is widely used in healthcare; however, the highly hydrophobic nature of the PPM readily adsorbs proteins and polysaccharides, which are conducive to bacteria being retained in the network, resulting in biofouling. Therefore, to improve the hydrophilic and antimicrobial properties of PPM, acrylic acid (AA) was first graft-polymerized on PPM (PPM- g-AA) by ultraviolet (UV)-induced photo-grafting polymerization. Chitosan (CS) was then covalently grafted onto PPM- g-AA to obtain the bigrafted PPM (PPM- g-AA- g-CS). Finally, silver (Ag) nanoparticles were immobilized onto PPM- g-AA- g-CS to create the hydrophilic and antibacterial PPM. The surface chemical composition and morphology of the samples were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The hydrophilic and antimicrobial properties of the modified PPM were assessed using static water contact angle measurements, wetting time, and bacteria colony-counting assays. The results show that PPM- g-AA- g-CS with immobilized Ag nanoparticles has excellent antibacterial and hydrophilic properties.

Download Full-text

Synthesis of a Superhydrophobic Polyvinyl Alcohol Sponge Using Water as the Only Solvent for Continuous Oil-Water Separation

Journal of Chemistry ◽

10.1155/2019/7153109 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Junyong Chen ◽

Junhui Xiang ◽

Xian Yue ◽

Huaxin Li ◽

Xianbo Yu

Keyword(s):

Contact Angle ◽

Polyvinyl Alcohol ◽

Separation Efficiency ◽

Water Contact ◽

Water Separation ◽

Long Term Stability ◽

Static Water ◽

Oil Water Separation ◽

Oil Water

Few cases of hydrophobic materials synthesized in water have been reported. In this work, water, as the only solvent, is used to prepare a superhydrophobic sponge via a facile and environment-friendly route. The as-prepared sponge, namely silylated polyvinyl alcohol (PVA) sponge, exhibits superhydrophobic and superoleophilic characters. It has the static water contact angle (WCA) of 152 ± 1 and the static oil contact angle (OCA) of 0°, which can lead to excellent selectivity for oil-water separation. Besides, the methyltriethoxysilane (MTES) can form a stable mixed structure with the PVA skeleton, resulting in the rare shedding of polymethylsiloxane nanoparticles and the long-term stability for oil-water separation. Furthermore, the silylated sponge shows a high separation efficiency (>99.6%), removing oil up to 6200∼14000 times of its own mass. The findings demonstrated that the silylated superhydrophobic sponge can be a promising candidate in water treatment application.

Download Full-text

Nanostructured Polymer Brushes With Reversibly Changing Properties

MRS Proceedings ◽

10.1557/proc-727-r2.5 ◽

2002 ◽

Vol 727 ◽

Author(s):

Denys Usov ◽

Manfred Stamm ◽

Sergiy Minko ◽

Christian Froeck ◽

Andreas Scholl ◽

...

Keyword(s):

Polymer Brushes ◽

Phase Segregation ◽

Water Contact ◽

Angle Measurements ◽

Nanostructured Polymer ◽

Contact Angle Measurements ◽

Vertical Segregation ◽

Oxygen Plasma Etching ◽

Grafting From ◽

Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Download Full-text

Facile Bio-Fabrication of Ag-Cu-Co Trimetallic Nanoparticles and Its Fungicidal Activity against Candida auris

Journal of Fungi ◽

10.3390/jof7010062 ◽

2021 ◽

Vol 7 (1) ◽

pp. 62 ◽

Cited By ~ 1

Author(s):

Majid Rasool Kamli ◽

Vartika Srivastava ◽

Nahid H. Hajrah ◽

Jamal S. M. Sabir ◽

Khalid Rehman Hakeem ◽

...

Keyword(s):

Electron Microscopy ◽

Antimicrobial Properties ◽

Bloodstream Infections ◽

Multidrug Resistant ◽

Biologically Active ◽

Phase Cell ◽

Candida Auris ◽

Medical Problems ◽

One Pot ◽

X Ray

Candida auris is an emergent multidrug-resistant pathogen that can lead to severe bloodstream infections associated with high mortality rates, especially in hospitalized individuals suffering from serious medical problems. As Candida auris is often multidrug-resistant, there is a persistent demand for new antimycotic drugs with novel antifungal action mechanisms. Here, we reported the facile, one-pot, one-step biosynthesis of biologically active Ag-Cu-Co trimetallic nanoparticles using the aqueous extract of Salvia officinalis rich in polyphenols and flavonoids. These medicinally important phytochemicals act as a reducing agent and stabilize/capping in the nanoparticles’ fabrication process. Fourier Transform-Infrared, Scanning electron microscopy, Transmission Electron Microscopy, Energy dispersive X-Ray, X-ray powder diffraction and Thermogravimetric analysis (TGA) measurements were used to classify the as-synthesized nanoparticles. Moreover, we evaluated the antifungal mechanism of as-synthesized nanoparticles against different clinical isolates of C. auris. The minimum inhibitory concentrations and minimum fungicidal concentrations ranged from 0.39–0.78 μg/mL and 0.78–1.56 μg/mL. Cell count and viability assay further validated the fungicidal potential of Ag-Cu-Co trimetallic nanoparticles. The comprehensive analysis showed that these trimetallic nanoparticles could induce apoptosis and G2/M phase cell cycle arrest in C. auris. Furthermore, Ag-Cu-Co trimetallic nanoparticles exhibit enhanced antimicrobial properties compared to their monometallic counterparts attributed to the synergistic effect of Ag, Cu and Co present in the as-synthesized nanoparticles. Therefore, the present study suggests that the Ag-Cu-Co trimetallic nanoparticles hold the capacity to be a lead for antifungal drug development against C. auris infections.

Download Full-text

On the Effectiveness of Oxygen Plasma and Alkali Surface Treatments to Modify the Properties of Polylactic Acid Scaffolds

Polymers ◽

10.3390/polym13101643 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1643

Author(s):

Ricardo Donate ◽

María Elena Alemán-Domínguez ◽

Mario Monzón

Keyword(s):

Surface Properties ◽

Enzymatic Degradation ◽

Oxygen Plasma ◽

Physicochemical Characterization ◽

Surface Treatments ◽

Carboxyl Groups ◽

Scanning Calorimetry ◽

Water Contact ◽

Angle Measurements ◽

3D Printed

Surface modification of 3D-printed PLA structures is a major issue in terms of increasing the biofunctionality and expanding the tissue engineering applications of these parts. In this paper, different exposure times were used for low-pressure oxygen plasma applied to PLA 3D-printed scaffolds. Alkali surface treatments were also evaluated, aiming to compare the modifications introduced on the surface properties by each strategy. Surface-treated samples were characterized through the quantification of carboxyl groups, energy-dispersive X-ray spectroscopy, water contact angle measurements, and differential scanning calorimetry analysis. The change in the surface properties was studied over a two-week period. In addition, an enzymatic degradation analysis was carried out to evaluate the effect of the surface treatments on the degradation profile of the 3D structures. The physicochemical characterization results suggest different mechanism pathways for each type of treatment. Alkali-treated scaffolds showed a higher concentration of carboxyl groups on their surface, which enhanced the enzymatic degradation rate, but were also proven to be more aggressive towards 3D-printed structures. In contrast, the application of the plasma treatments led to an increased hydrophilicity of the PLA surface without affecting the bulk properties. However, the changes on the properties were less steady over time.

Download Full-text

Epoxy/alumina composite coating on welded steel 316L with excellent wear and anticorrosion properties

Scientific Reports ◽

10.1038/s41598-021-91741-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maryama Hammi ◽

Younes Ziat ◽

Zakaryaa Zarhri ◽

Charaf Laghlimi ◽

Abdelaziz Moutcine

Keyword(s):

Electrochemical Behaviour ◽

Sem Analysis ◽

Water Contact ◽

Welded Steel ◽

Melted Zone ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Alumina Composite ◽

The Cost ◽

Good Contrast

AbstractThe main purpose of this study is to elaborate anticorrosive coatings for the welded steel 316L, since this later is widely used in industrial field. Hence, within this work we have studied the electrochemical behaviour of different zones of the welded steel 316 in 1 M HCl media. The macrography study of the welded steel has revealed the different areas with a good contrast. We have stated three different zones, namely; melted zone (MZ), heat affected zone (HAZ) and base metal zone (BM). Impedance studies on welded steel 316L were conducted in 1 M HCl solution, coating of Epoxy/Alumina composite was applied on different zones, in order to reveal the anti-corrosion efficiency in each zone. Scanning electron microscopy (SEM) analysis was undertaken in order to check how far the used coating in such aggressive media protects the studied zones and these findings were assessed by water contact angle measurements. The choice of this coating is based on the cost and the safety. We concluded that the Epoxy/Alumina composite has a good protecting effect regarding welded steel in aggressive media.

Download Full-text

Physico-Chemical Characterization and Antimicrobial Properties of Hybrid Film Based on Saponite and Phloxine B

Molecules ◽

10.3390/molecules26020325 ◽

2021 ◽

Vol 26 (2) ◽

pp. 325

Author(s):

Nitin Chandra teja Dadi ◽

Matúš Dohál ◽

Veronika Medvecká ◽

Juraj Bujdák ◽

Kamila Koči ◽

...

Keyword(s):

Hybrid Film ◽

Antimicrobial Properties ◽

Chemical Characterization ◽

Layered Silicate ◽

Contact Angles ◽

Exchange Capacity ◽

Resistant Bacteria ◽

Hybrid Films ◽

Water Contact ◽

Physico Chemical

This research was aimed at the preparation of a hybrid film based on a layered silicate saponite (Sap) with the immobilized photosensitizer phloxine B (PhB). Sap was selected because of its high cation exchange capacity, ability to exfoliate into nanolayers, and to modify different surfaces. The X-ray diffraction of the films confirmed the intercalation of both the surfactant and PhB molecules in the Sap film. The photosensitizer retained its photoactivity in the hybrid films, as shown by fluorescence spectra measurements. The water contact angles and the measurement of surface free energy demonstrated the hydrophilic nature of the hybrid films. Antimicrobial effectiveness, assessed by the photodynamic inactivation on hybrid films, was tested against a standard strain and against methicillin-resistant bacteria of Staphylococcus aureus (MRSA). One group of samples was irradiated (green LED light; 2.5 h) and compared to nonirradiated ones. S. aureus strains manifested a reduction in growth from 1-log10 to over 3-log10 compared to the control samples with Sap only, and defects in S. aureus cells were proven by scanning electron microscopy. The results proved the optimal photo-physical properties and anti-MRSA potential of this newly designed hybrid system that reflects recent progress in the modification of surfaces for various medical applications.

Download Full-text

Cellulose Acetate-Based Electrospun Materials with a Variety of Biological Potentials: Antibacterial, Antifungal and Anticancer

Polymers ◽

10.3390/polym13101631 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1631

Author(s):

Mariya Spasova ◽

Nevena Manolova ◽

Iliya Rashkov ◽

Petya Tsekova ◽

Ani Georgieva ◽

...

Keyword(s):

Cellulose Acetate ◽

Mechanical Tests ◽

Fibrous Materials ◽

Water Contact ◽

Antibacterial And Antifungal Activities ◽

3T3 Fibroblasts ◽

Angle Measurements ◽

Zones Of Inhibition ◽

Model Drug ◽

Antibacterial And Antifungal

Novel eco-friendly fibrous materials with complex activities from cellulose acetate and cellulose acetate/polyethylene glycol (CA,PEG) containing 5-chloro-8-hydroxyquinoline as a model drug were obtained by electrospinning. Several methods, including scanning electron microscopy, X-ray diffraction analysis, ultraviolet-visible spectroscopy, water contact angle measurements, and mechanical tests, were utilized to characterize the obtained materials. The incorporation of PEG into the fibers facilitated the drug release. The amounts of the released drug from CA/5-Cl8Q and CA,PEG/5-Cl8Q were 78 ± 3.38% and 86 ± 3.02%, respectively (for 175 min). The antibacterial and antifungal activities of the obtained materials were studied. The measured zones of inhibition of CA/5-Cl8Q and CA,PEG/5-Cl8Q mats were 4.0 ± 0.18 and 4.5 ± 0.2 cm against S. aureus and around 4.0 ± 0.15 and 4.1 ± 0.22 cm against E. coli, respectively. The complete inhibition of the C. albicans growth was detected. The cytotoxicity of the obtained mats was tested toward HeLa cancer cells, SH-4 melanoma skin cells, and mouse BALB/c 3T3 fibroblasts as well. The CA/5-Cl8Q and CA,PEG/5-Cl8Q materials exhibited anticancer activity and low normal cell toxicity. Thus, the obtained fibrous materials can be suitable candidates for wound dressing applications and for application in local cancer treatment.

Download Full-text

Use of the photoaffinity cross-linking agent N-hydroxysuccinimidyl-4-azidosalicylic acid to characterize salivary-glycoprotein-bacterial interactions

Biochemical Journal ◽

10.1042/bj2340043 ◽

1986 ◽

Vol 234 (1) ◽

pp. 43-48 ◽

Cited By ~ 33

Author(s):

E J Bergey ◽

M J Levine ◽

M S Reddy ◽

S D Bradway ◽

I Al-Hashimi

Keyword(s):

Polyacrylamide Gel Electrophoresis ◽

Specific Interaction ◽

Gel Filtration ◽

Cross Linking ◽

Oral Streptococci ◽

Bacterial Surface ◽

Acetylneuraminic Acid ◽

Streptococcus Sanguis ◽

Surface Examination ◽

Inhibition Studies

The present study has utilized the iodinatable cross-linking agent N-hydroxysuccinimidyl-4-azidosalicylic acid (ASA) to examine the specific interaction between the proline-rich glycoprotein (PRG) of human parotid saliva and Streptococcus sanguis G9B. The binding of 125I-ASA-PRG to Streptococcus sanguis G9B displayed saturation kinetics, reversibility and was inhibited by unlabelled PRG. Inhibition studies with other glycoproteins and saccharides indicated that binding was mediated by a bacterial adhesin with specificity towards N-acetylneuraminic acid, galactose, and N-acetylgalactosamine. After cross-linking, the 125I-ASA-PRG-adhesin complex could be extracted with SDS and separated from uncoupled 125I-ASA-PRG by gel filtration on Sepharose CL-6B. Approx. 1% of the 125I-ASA-PRG was cross-linked to the bacterial surface. Examination of the 125I-ASA-PRG-adhesin complex by SDS/polyacrylamide-gel electrophoresis/fluorography on 5% -(w/v)-polyacrylamide gels revealed that PRG was bound to two bacterial components. These findings support our previous suggestion that human salivary glycoproteins can specifically interact with oral streptococci and that these interactions occur between the glycoprotein's carbohydrate units and lectin(s) on the bacterial cell surface.

Download Full-text

PLA-Based Hybrid and Composite Electrospun Fibrous Scaffolds as Potential Materials for Tissue Engineering

Journal of Nanomaterials ◽

10.1155/2017/9246802 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 9

Author(s):

Anna Magiera ◽

Jarosław Markowski ◽

Elzbieta Menaszek ◽

Jan Pilch ◽

Stanislaw Blazewicz

Keyword(s):

Tissue Engineering ◽

Mechanical Tests ◽

Hybrid Structures ◽

Poly Lactic Acid ◽

Electrospinning Technique ◽

Water Contact ◽

Human Osteoblasts ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Normal Human

The aim of the study was to manufacture poly(lactic acid)- (PLA-) based nanofibrous nonwovens that were modified using two types of modifiers, namely, gelatin- (GEL-) based nanofibres and carbon nanotubes (CNT). Hybrid nonwovens consisting of PLA and GEL nanofibres (PLA/GEL), as well as CNT-modified PLA nanofibres with GEL nanofibres (PLA + CNT/GEL), in the form of mats, were manufactured using concurrent-electrospinning technique (co-ES). The ability of such hybrid structures as potential scaffolds for tissue engineering was studied. Both types of hybrid samples and one-component PLA and CNTs-modified PLA mats were investigated using scanning electron microscopy (SEM), water contact angle measurements, and biological and mechanical tests. The morphology, microstructure, and selected properties of the materials were analyzed. Biocompatibility and bioactivity in contact with normal human osteoblasts (NHOst) were studied. The coelectrospun PLA and GEL nanofibres retained their structures in hybrid samples. Both types of hybrid nonwovens were not cytotoxic and showed better osteoinductivity in comparison to scaffolds made from pure PLA. These samples also showed significantly reduced hydrophobicity compared to one-component PLA nonwovens. The CNT-contained PLA nanofibres improved mechanical properties of hybrid samples and such a 3D system appears to be interesting for potential application as a tissue engineering scaffold.

Download Full-text