scholarly journals Incorporation and antimicrobial activity of nisin Z within carrageenan/chitosan multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessie L. Webber ◽  
Rashin Namivandi-Zangeneh ◽  
Sławomir Drozdek ◽  
Kazimiera A. Wilk ◽  
Cyrille Boyer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Properties ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Bilayer Film ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nisin Z ◽  
Mrsa Strains ◽  
Industry Sectors

AbstractAn antimicrobial peptide, nisin Z, was embedded within polyelectrolyte multilayers (PEMs) composed of natural polysaccharides in order to explore the potential of forming a multilayer with antimicrobial properties. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR), the formation of carrageenan/chitosan multilayers and the inclusion of nisin Z in two different configurations was investigated. Approximately 0.89 µg cm−2 nisin Z was contained within a 4.5 bilayer film. The antimicrobial properties of these films were also investigated. The peptide containing films were able to kill over 90% and 99% of planktonic and biofilm cells, respectively, against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) strains compared to control films. Additionally, surface topography and wettability studies using atomic force microscopy (AFM) and the captive bubble technique revealed that surface roughness and hydrophobicity was similar for both nisin containing multilayers. This suggests that the antimicrobial efficacy of the peptide is unaffected by its location within the multilayer. Overall, these results demonstrate the potential to embed and protect natural antimicrobials within a multilayer to create functionalised coatings that may be desired by industry, such as in the food, biomaterials, and pharmaceutical industry sectors.

A Novel Cell Co-Culture Method Utilizing Thermo-Responsive Surface

2007 ◽  
Vol 342-343 ◽  
pp. 221-224
Author(s):  
Jin Suk Bae ◽  
Ga Young Jun ◽  
Akihiko Kikuchi ◽  
Teruo Okano ◽  
Chang Hyun Ahn ◽  
...  
Keyword(s):  
Contact Angle ◽  
Electron Spectroscopy ◽  
Electron Beam Irradiation ◽  
Culture Method ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Beam Irradiation ◽  
Cover Glass ◽  
Force Microscopy ◽  
Atomic Force

In this work, we developed a novel patterned co-culture method with thermo-responsive poly(N-isopropylacrylamide) (PIPAAm) and poly(N-ρ-vinylbenzyl-Ο-β-D-galactopyranosyl-(1→ 4)-D-gluconamide) (PVLA) inducing active hepatocyte attachment. Patterned graft of PIPAAm onto PS dishes was carried out by electron beam irradiation using cover-glass as a photomask. PVLA was only coated onto PIPAAm-ungrafted domain because of hydrated hydrophilic property of PIPAAm at below the LCST. Analysis by attenuated total reflection-Fourier transform infrared and electron spectroscopy for chemical analysis revealed that PIPAAm and PVLA were successfully grafted and coated on surfaces of PS dishes. PIPAAm-grafted surface exhibited decreasing contact angle by changing temperature from 37 to 20°C, while PVLA-coated PS and non-treated PS had negligible contact angle changes with temperature alternation. Atomic force microscopy (AFM) results showed that PIPAAm-grafted and PVLA-coated PS had smoother surfaces than that of ungrafted PS dishes. After culture for 12 hours, hepatocytes were well attached on PVLA-coated domain. Hepatocytes adherent on PIPAAm-grafted domain were detached by decreasing temperature. And then, fibroblasts were seeded onto PIPAAm pattern-grafted domain. Fibroblasts were only attached and spread onto PIPAAm-grafted domain. Co-cultured hepatocytes showed better differentiated function of albumin expression compared to homotypic hepatocyte culture

Combined in situ atomic force microscopy and infrared attenuated total reflection spectroelectrochemistry

The Analyst ◽  
2013 ◽  
Vol 138 (22) ◽  
pp. 6746 ◽  
Author(s):  
Daniel Neubauer ◽  
Jochen Scharpf ◽  
Alberto Pasquarelli ◽  
Boris Mizaikoff ◽  
Christine Kranz
Keyword(s):  
Atomic Force Microscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Morphology and Physicochemical Properties of Branched Polyurethane/Biopolymer Blends

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 16 ◽  
Author(s):  
Joanna Brzeska ◽  
Agnieszka Tercjak ◽  
Wanda Sikorska ◽  
Marek Kowalczuk ◽  
Maria Rutkowska
Keyword(s):  
Thermal Stability ◽  
Water Drop ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Thermal Stability Of ◽  
Biopolymer Blends

The aim of this study is the analyze the structure of branched polyurethanes based on synthetic poly([R,S]-3-hydroxybutyrate) and their blends with biopolymers and montmorillonite. The properties which would predict the potential susceptibility of these materials to degradation are also estimated. Fourier-transform infrared spectroscopy with attenuated total reflection analysis shows that poly([d,l]-lactide) is on the surfaces of polyurethanes, whereas chitosan and starch are included inside the blend network. Atomic force microscopy images have shown that the surfaces of investigated samples are heterogenous with the formation of spherulites in case of pure polyurethanes. The presence of biopolymers in the blend reduced the crystallinity of polyurethanes. Thermal stability of blends of polyurethanes with poly([d,l]-lactide) and polysaccharides decreased in comparison to pure polyurethanes. Although the tensile strength is reduced after the blending of polyurethanes with biopolymers, the elongation at break increased, especially in the case of polyurethane/poly([d,l]-lactide) blends. The presence of polysaccharides in the obtained blends caused the significant reduction of contact angle after one minute from water drop immersion. This hydrophilizing effect is the highest when montmorillonite has been incorporated into the chitosan blend. The estimated properties of the obtained materials suggest their potential sensitivity on environmental conditions.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

scholarly journals Surface Morphology of Single and Multi-Layer Silicon Nitride Dielectric Nano-Coatings on Silicon Dioxide and Polycrystalline Silicon

2019 ◽  
Vol 26 (1) ◽  
pp. 25-29
Author(s):  
Liga AVOTINA ◽  
Elina PAJUSTE ◽  
Marina ROMANOVA ◽  
Gennady ENICHEK ◽  
Aleksandrs ZASLAVSKIS ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Surface Morphology ◽  
Polycrystalline Silicon ◽  
Chemical Vapour ◽  
Attenuated Total Reflection ◽  
Infrared Spectrometry ◽  
Chemical Bonds ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pressure Chemical

Silicon nitride (Si3N4) in a form of single and multi-layer nanofilms is proposed to be used as a dielectric layer in nanocapacitors for operation in harsh environmental conditions. Characterization of surface morphology, roughness and chemical bonds of the Si3N4 coatings has an important role in production process as the surface morphology affects the contact surface with other components of the produced device. Si3N4 was synthesized by using low pressure chemical vapour deposition method and depositing single and multi-layer (3 – 5 layers) nanofilms on SiO2 and polycrystalline silicon (PolySi). The total thickness of the synthesized nanofilms was 20 – 60 nm. Surface morphology was investigated by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical bonds in the layers were identified by means of Fourier transform infrared spectrometry, attenuated total reflection (FTIR-ATR) method. (From the SEM and AFM images it was estimated that both single and multi-layer coatings are deposited homogenously. Si-N breathing and stretching modes are observed in FTIR spectra and the surface morphology is highly dependent on PolySi, therefore suggesting the decrease of the roughness of the bottom electrode for use in the nanocapacitors.

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