scholarly journals Biomimetic Surfaces via Dextran Immobilization: Grafting Density and Surface Properties

2004 ◽  
Vol 826 ◽  
Author(s):  
Davide Miksa ◽  
Elizabeth R. Irish ◽  
Dwayne Chen ◽  
Russell J. Composto ◽  
David M. Eckmann
Keyword(s):  
Contact Angle ◽  
Surface Oxidation ◽  
Sodium Metaperiodate ◽  
Oxidized Dextran ◽  
Force Microscopy ◽  
Biomimetic Surfaces ◽  
H Nmr ◽  
Atomic Force ◽  
Angle Data ◽  
Contact Angle Analysis

AbstractBiomimetic surfaces were prepared by chemisorption of oxidized dextran (Mw = 110 kDa) onto SiO2 substrates that were previously modified with aminopropyl-tri-ethoxy silane (APTES). The kinetics of dextran oxidation by sodium metaperiodate (NaIO4) were quantified by 1H NMR and pH measurements. The extent of oxidation was then used to control the morphology of the biomimetic surface. Oxidation times of 0.5, 1, 2, 4, and 24 hours resulted in <20, ∼30, ∼40, ∼50 and 100% oxidation, respectively. The surfaces were characterized by contact angle analysis and atomic force microscopy (AFM). Surfaces prepared with low oxidation times revealed a more densely packed “brushy” layer when imaged by AFM than those prepared at low oxidation times. Finally, the contact angle data revealed, quite unexpectedly, that the surface with the greatest entropic freedom (0.5 h) wetted the fastest and to the greatest extent (θAPTES>θ1h>θ2,4h>θ0.5h).

scholarly journals Dynamic Contact Angle Analysis of Protein Adsorption on Polysaccharide Multilayer’s Films for Biomaterial Reendothelialization

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Safiya Benni ◽  
Thierry Avramoglou ◽  
Hanna Hlawaty ◽  
Laurence Mora
Keyword(s):  
Contact Angle ◽  
Endothelial Cell ◽  
Protein Adsorption ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Endothelial Cell Response ◽  
Adsorption Desorption ◽  
Contact Angle Analysis

Atherosclerosis is a major cardiovascular disease. One of the side effects is restenosis. The aim of this work was to study the coating of stents by dextran derivates based polyelectrolyte’s multilayer (PEM) films in order to increase endothelialization of injured arterial wall after stent implantation. Films were composed with diethylaminoethyl dextran (DEAE) as polycation and dextran sulphate (DS) as polyanion. One film was composed with 4 bilayers of (DEAE-DS)4and was labeled D−. The other film was the same as D− but with an added terminal layer of DEAE polycation: (DEAE-DS)4-DEAE (labeled D+). The dynamic adsorption/desorption of proteins on the films were characterized by dynamic contact angle (DCA) and atomic force microscopy (AFM). Human endothelial cell (HUVEC) adhesion and proliferation were quantified and correlated to protein adsorption analyzed by DCA for fibronectin, vitronectin, and bovine serum albumin (BSA). Our results showed that the endothelial cell response was optimal for films composed of DS as external layer. Fibronectin was found to be the only protein to exhibit a reversible change in conformation after desorption test. This behavior was only observed for (DEAE-DS)4films. (DEAE-DS)4films could enhance HUVEC proliferation in agreement with fibronectin ability to easily change from conformation.

Effect of Water Temperature, pH Value, and Film Thickness on the Wettability Behaviour of Copper Surfaces Coated with Copper Using EB-PVD Technique

2019 ◽  
Vol 60 ◽  
pp. 124-141 ◽  
Author(s):  
Naser Ali ◽  
Joao Amaral Teixeira ◽  
Abdulmajid Addali
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Film Thickness ◽  
Water Temperature ◽  
Ph Value ◽  
Surface Wettability ◽  
Copper Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Static Contact

This research investigates the effect of surface roughness, water temperature, and pH value on the wettability behaviour of copper surfaces. An electron beam physical vapour deposition technique was used to fabricate 25, 50, and 75 nm thin films of copper on the surface of copper substrates. Surface topographical analysis, of the uncoated and coated samples, was performed using an atomic force microscopy device to observe the changes in surface microstructure. A goniometer device was then employed to examine the surface wettability of the samples by obtaining the static contact angle between the liquid and the attached surface using the sessile drops technique. Waters of pH 4, 7, and 9 were employed as the contact angle testing fluids at a set of fixed temperatures that ranged from 20°C to 60°C. It was found that increasing the deposited film thickness reduces the surface roughness of the as-prepared copper surfaces and thus causing the surface wettability to diverge from its initial hydrophobic nature towards the hydrophilic behaviour region. A similar divergence behaviour was seen with the rise in temperature of water of pH 4, and 9. In contrast, the water of pH 7, when tested on the uncoated surface, ceased to reach a contact angle below 90o. It is believed that the observed changes in surface wettability behaviour is directly linked to the liquid temperature, pH value, surface roughness, along with the Hofmeister effect between the water and the surface in contact.

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

scholarly journals Separation of Water/Oil Emulsions by an Electrospun Copolyamide Mat Covered with a 2D Ti3C2Tx MXene

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3171
Author(s):  
AbdolAli Moghaddasi ◽  
Patrik Sobolčiak ◽  
Anton Popelka ◽  
Igor Krupa
Keyword(s):  
Contact Angle ◽  
Vegetable Oil ◽  
Separation Efficiency ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Oil Emulsions ◽  
Uv Transmittance ◽  
Stock Solutions

Purpose: Copolyamide 6,10 (coPA) electrospun mats were covered with multilayered (ML) and single-layered (SL) MXene (Ti3C2Tx) as a membrane for the separation of water/vegetable oil emulsions. Methods: Prepared membranes were characterized by atomic force microscopy (AFM), profilometry, the contact angle measurements of various liquids in air, and the underwater contact angle of vegetable oil. The separation efficiency was evaluated by measuring the UV transmittance of stock solutions compared to the UV transmittance of the filtrate. Results: The MXene coating onto coPA mats led to changes in the permeability, hydrophilicity, and roughness of the membranes and enhanced the separation efficiency of the water/vegetable oil emulsions containing 10, 100, and 1000 ppm of sunflower vegetable oil. It was found that membranes were highly oleophobic (>124°) under water, unlike in air, where the membranes showed high oleophobicity (<5°). The separation efficiency of water/oil emulsions for both types of covered membranes reached over 99%, with a surface coverage of 3.2 mg/cm2 Ti3C2Tx (for ML-Ti3C2Tx) and 2.9 mg/cm2 (for SL-Ti3C2Tx). Conclusions: The separation efficiency was greater than 98% for membranes covered with 2.65 mg/cm2 of ML-Ti3C2Tx, whereas the separation efficiency for membranes containing 1.89 and 0.77 mg/cm2 was less than 90% for all studied emulsion concentrations.

scholarly journals Synthesis and Characterization of Polycarbonate Copolymers Containing Benzoyl Groups on the Side Chain for Scratch Resistance

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Hohyoun Jang ◽  
Jaeseong Ha ◽  
Jiho Yoo ◽  
Jaeseung Pyo ◽  
Kunyoung Choi ◽  
...  
Keyword(s):  
Methylene Chloride ◽  
Water Drop ◽  
Scratch Resistance ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
H Nmr ◽  
Chemical Structures ◽  
Atomic Force ◽  
Rearrangement Reaction ◽  
Surface Morphologies

The purpose of this study was to enhance the scratch resistance of polycarbonate copolymer by using 3,3′-dibenzoyl-4,4′-dihydroxybiphenyl (DBHP) monomer, containing benzoyl moieties on the ortho positions. DBHP monomer was synthesized from 4,4′-dihydroxybiphenyl and benzoyl chloride, followed by the Friedel-Craft rearrangement reaction with AlCl3. The polymerizations were conducted following the low-temperature procedure, which is carried out in methylene chloride by using triphosgene, triethylamine, bisphenol-A, and DBHP. The chemical structures of the polycarbonate copolymers were confirmed by1H-NMR. The thermal properties of copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry, and also surface morphologies were assessed by atomic force microscopy. The scratch resistance of homopolymer film (100 μm) changed from 6B to 1B, and the contact angle of a sessile water drop onto the homopolymer film also increased.

scholarly journals Surface Properties of Alginate/Chitosan Biofilm for Wound Healing Application

2020 ◽  
Vol 1010 ◽  
pp. 602-607
Author(s):  
Maizlinda Izwana Idris ◽  
Mohammed Firdaus Adzhari ◽  
Siti Natrah Abdul Bakil ◽  
Tee Chuan Lee ◽  
Mohamad Ali Selimin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wound Healing ◽  
Surface Properties ◽  
Healing Process ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Force Microscopy ◽  
Good Surface ◽  
Atomic Force ◽  
Biopolymer Film

This work focuses on the fabrication of film based on natural biopolymers for wound healing application. Alginate and chitosan were choosen because of their oustanding properties such as biocompatible, hydrophilic and non-toxic. Earlier, the biopolymer film was fabricated by using alginate 1% wt and chitosan 1% wt. solutions at volume ratios of 99:1 and 97:3. Next, the biopolymer film solution was cross-linked with 1M CaCl2.2H2O for two hours and later dried for 24 hours at room temperature. Then, the surface properties of the prepared biopolymer films were characterised via Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM) and contact angle measurement. It was observed that the surface of the biopolymer film became rougher as the volume of the chitosan increases. This condition was confirmed with average surface roughness, RA for biopolymer film with ratio of 97:3 resulted in higher values. Also it was found that the surface of biopolymer films were hydrophilic after the contact angle was less than 90°. This can be concluded that the biopolymer based on alginate/chitosan is a promising candidate for wound healing materials particularly with good surface properties for faster healing process at the wound areas.

Biopolymer Blends as Potential Biomaterials and Cosmetic Materials

2013 ◽  
Vol 583 ◽  
pp. 95-100 ◽  
Author(s):  
Alina Sionkowska ◽  
Katarzyna Lewandowska ◽  
A. Planecka ◽  
P. Szarszewska ◽  
K. Krasinska ◽  
...  
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Silk Fibroin ◽  
High Surface ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Contact Angle Measurements

Blends of two polymer, namely chitosan with silk fibroin or partially hydrolysed polyacrylamide (HPAM) were prepared. The surface properties of chitosan/silk fibroin and chitosan/HPAM blended films were investigated using the technique of Atomic Force Microscopy (AFM) and by means of contact angle measurements allowing the calculation of surface free energy. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films and chitosan/silk fibroin films were made and surface free energy was calculated. It was found that chitosan/silk fibroin blend surface is enriched in high surface energy component i.e. silk fibroin. The surface roughness of chitosan, silk fibroin, HPAM, chitosan/silk fibroin and chitosan/HPAM blended films differs with the composition of the blend. Film-forming polymeric blends can be potentially used as biomaterials and cosmetic materials.

scholarly journals AFM-based High-Throughput Nanomechanical Screening of Single Extracellular Vesicles

2019 ◽  
Author(s):  
Andrea Ridolfi ◽  
Marco Brucale ◽  
Costanza Montis ◽  
Lucrezia Caselli ◽  
Lucia Paolini ◽  
...  
Keyword(s):  
Contact Angle ◽  
Spherical Shape ◽  
Direct Consequence ◽  
Calibration Procedure ◽  
Morphological Characterization ◽  
Adhesion Forces ◽  
Mechanical Stiffness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oblate Spheroids

AbstractWe herein describe an Atomic Force Microscopy (AFM)-based experimental procedure which allows the simultaneous mechanical and morphological characterization of several hundred individual nanosized vesicles within the hour timescale.When deposited on a flat rigid surface from aqueous solution, vesicles are deformed by adhesion forces into oblate spheroids whose geometry is a direct consequence of their mechanical stiffness. AFM image analysis can be used to quantitatively measure the contact angle of individual vesicles, which is a size-independent descriptor of their deformation and, consequently, of their stiffness. The same geometrical measurements can be used to infer vesicle diameter in its original, spherical shape.We demonstrate the applicability of the proposed approach to natural vesicles obtained from different sources, recovering their size and stiffness distributions by simple AFM imaging in liquid. We show how the combined EV stiffness/size readout is able to discriminate between subpopulations of vesicular and non-vesicular objects in the same sample, and between populations of vesicles with similar sizes but different mechanical characteristics. We also discuss a force spectroscopy calibration procedure to quantitatively link the stiffness of EVs to their average contact angle.Finally, we discuss expected extensions and applications of the methodology.

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