Deposition of organic−inorganic hybrid coatings over 316L surgical stainless steel and evaluation on vascular cells

2014 ◽  
Vol 92 (10) ◽  
pp. 987-995 ◽  
Author(s):  
F.G. Doro ◽  
A.P. Ramos ◽  
J.F. Schneider ◽  
U.P. Rodrigues-Filho ◽  
M.A.M.S. Veiga ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Phosphate Buffer Solution ◽  
Hybrid Coatings ◽  
Stainless Steel Surface ◽  
Buffer Solution ◽  
Migration Assay ◽  
Mechanical Adhesion ◽  
Drug Eluting

Surface coating of metallic materials using the sol-gel technique is a suitable approach to obtain hybrid materials with improved properties for biomedical applications. In this study, an AISI 316L stainless steel surface was coated with ormosils prepared from tetraethylsiloxane and 3-glycidoxypropyltrimethoxysilane or polydimethylsiloxane. The characterization of structural and surface properties was performed by several techniques. Surface microstructure, morphology, and energy are dependent on organosilane type and content. Chemical stability of coatings was investigated by static immersion tests in phosphate buffer solution at 37 °C, and silicon leaching after 21 days was found to be in the range of ∼200−300 μg L−1. Mechanical adhesion was found to be within 1.0 and 3.7 N cm−1. The interaction of the samples and materials in the cardiovascular environment was investigated through cellular behavior. Biological assays were performed with slides to avoid any cytotoxic effects on human endothelial cells (HUVEC) and rabbit arterial smooth muscle cells (RASM). No significant alterations were observed after 24 h in the viability of RASM and HUVEC cells exposed to different coatings. No increase of HUVEC or RASM migration was observed after 24 h as evaluated by transwell migration assay. The hybrid materials showed suitable properties for potential application as biomaterials in cardiovascular environment as well as for incorporation of bioactive species with the aim to prepare drug-eluting stents.

Improved Quantitative Recovery of Listeria monocytogenes from Stainless Steel Surfaces Using a One-Ply Composite Tissue

2004 ◽  
Vol 67 (10) ◽  
pp. 2212-2217 ◽  
Author(s):  
KEITH L. VORST ◽  
EWEN C. D. TODD ◽  
ELLIOT T. RYSER
Keyword(s):  
Stainless Steel ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Steel Plates ◽  
Stainless Steel Surface ◽  
Disc Diffusion ◽  
Buffer Solution ◽  
Composite Tissue ◽  
Steel Surfaces ◽  
Diffusion Assay

Four sampling devices, a sterile environmental sponge (ES), a sterile cotton-tipped swab (CS), a sterile calcium alginate fiber-tipped swab (CAS), and a one-ply composite tissue (CT), were evaluated for quantitative recovery of Listeria monocytogenes from a food-grade stainless steel surface. Sterile 304-grade stainless steel plates (6 by 6 cm) were inoculated with approximately 106 CFU/cm2 L. monocytogenes strain Scott A and dried for 1 h. The ES and CT sampling devices were rehydrated in phosphate buffer solution. After plate swabbing, ES and CT were placed in 40 ml of phosphate buffer solution, stomached for 1 min and hand massaged for 30 s. Each CS and CAS device was rehydrated in 0.1% peptone before swabbing. After swabbing, CS and CAS were vortexed in 0.1% peptone for 1 min. Samples were spiral plated on modified Oxford agar with modified Oxford agar Rodac Contact plates used to recover any remaining cells from the stainless steel surface. Potential inhibition from CT was examined in both phosphate buffer solution and in a modified disc-diffusion assay. Recovery was 2.70, 1.34, and 0.62 log greater using CT compared with ES, CS, and CAS, respectively, with these differences statistically significant (P < 0.001) for ES and CT and for CAS, CS, and CT (P < 0.05). Rodac plates were typically overgrown following ES, positive after CS and CAS, and negative after CT sampling. CT was noninhibitory in both phosphate buffer solution and the modified disc-diffusion assay. Using scanning electron microscopy, Listeria cells were observed on stainless steel plates sampled with each sampling device except CT. The CT device, which is inexpensive and easy to use, represents a major improvement over other methods in quantifying L. monocytogenes on stainless steel surfaces and is likely applicable to enrichment of environmental samples.

Fabrication of an Electrochemical Sensor for Glucose Detection using ZnO Nanorods

MRS Advances ◽  
2016 ◽  
Vol 1 (13) ◽  
pp. 861-867 ◽  
Author(s):  
Sanghamitra Mandal ◽  
Mohammed Marie ◽  
Omar Manasreh
Keyword(s):  
Response Time ◽  
Glass Substrate ◽  
Glucose Sensor ◽  
Limit Of Detection ◽  
Sol Gel ◽  
Zno Nanorods ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Coated Glass Substrate ◽  
Coated Glass

ABSTRACTAn electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized and tested. The ZnO nanorods are synthesized on indium titanium oxide (ITO) coated glass substrate, using the hydrothermal sol-gel technique. The working principle of the sensor under investigation is based on the electrochemical reaction taking place between cathode and anode, in the presence of an electrolyte. A platinum plate, used as the cathode and Nafion/Glucose Oxidase/ZnO nanorods/ITO-coated glass substrate used as anode, is immersed in pH 7.0 phosphate buffer solution electrolyte to test for the presence of glucose. Several amperometric tests are performed on the fabricated sensor to determine the response time, sensitivity and limit of detection of the sensor. A fast response time less than 3 s with a high sensitivity of 1.151 mA cm-2mM-1 and low limit of detection of 0.089 mM is reported. The glucose sensor is characterized using the cyclic voltammetry method in the range from -0.8 – 0.8 V with a voltage scan rate of 100 mV/s.

scholarly journals Multilayer silica-methacrylate hybrid coatings prepared by sol–gel on stainless steel 316L: Electrochemical evaluation

2008 ◽  
Vol 202 (10) ◽  
pp. 2194-2201 ◽  
Author(s):  
Damián A. López ◽  
Nataly C. Rosero-Navarro ◽  
Josefina Ballarre ◽  
Alicia Durán ◽  
Mario Aparicio ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Sol Gel ◽  
Hybrid Coatings ◽  
Stainless Steel 316L ◽  
Electrochemical Evaluation

scholarly journals Chemical modification of TiO2 by H2PO4−/HPO42− anions using the sol-gel route with controlled precipitation and hydrolysis: enhancing thermal stability

2014 ◽  
Vol 32 (4) ◽  
pp. 617-625 ◽  
Author(s):  
Kais Elghniji ◽  
Mohamed Saad ◽  
Manel Araissi ◽  
Elimame Elaloui ◽  
Younes Moussaoui
Keyword(s):  
31P Nmr ◽  
Sol Gel ◽  
Phosphate Buffer Solution ◽  
Rutile Phase ◽  
Titanium Phosphate ◽  
Buffer Solution ◽  
Raman Analysis ◽  
Phosphate Species ◽  
Ft Ir ◽  
Controlled Precipitation

AbstractTwo titanium phosphate materials (TpP and ThP) have been successfully synthesized by sol-gel route with controlled precipitation and hydrolysis. The TpP material was obtained from the reaction between precipitated titania and phosphate buffer solution H2PO4− /HPO42− (pH = 7.3). The TpP material was prepared through hydrolysis of titanium in the presence of H2PO4−/HPO42. The probable state of the phosphate anions in titania framework and their effect on the anatase-to-rutile transformation were characterized by ICP-AES, DTA-TG, 31P NMR, FT-IR, and Raman analysis HRTEM/SEM. FT-IR and 31P NMR analyses of titanium phosphate TpP calcined at low temperature showed that the phosphate species existed not only as Ti-O-P in the bulk TiO2 but also as amorphous titanium phosphates, including bidentate Ti(HPO4)2 and monodentate Ti(H2PO4)4. Increased calcination temperature only gave an enrichment of bidentate structure on the titania surface. For the TpP material, H2PO4−/HPO42− anions were introduced into the initial solution, before precipitation, what promoted their lattice localization. At high temperatures, all the phosphorus inside the bulk of TiO2 migrated to the surface. The Raman analysis of both samples showed that the bidentate phosphates increased the temperature of the anatase-to-rutile phase transformation to more than 1000 °C with the formation of well crystalline TiP2O7 phase. This phenomenon was more evident for TpP sample.

Encapsulation of Urease in Molybdenum Trioxide Sol-Gel

2004 ◽  
Vol 828 ◽  
Author(s):  
Prashant K. Jha ◽  
P. I. Gouma
Keyword(s):  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Ph Value ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Phosphate Buffer Solution ◽  
Gaseous Ammonia ◽  
Buffer Solution ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTMolybdenum trioxide sol-gel matrices were tested for their ability to host biomaterials in their structures without adversely affecting the activity of the encapsulated biomolecules. The sol-gel composites were prepared at room temperature; the urease was added during the hydrolysis step to ensure proper encapsulation in the pore structure of the sol. Phosphate buffer solution was added during this stage to maintain the pH value of the sol in the bio-compatible range. The activity of incorporated urease was tested by exposing composite sol-gel material to standard urea test solutions and measuring the amount of gaseous ammonia (released by the reaction of urea with water in the presence of urease) using an ammonia electrode. The concentration of urea solutions ranged from 1mM to 10mM. An electronic olfactory system (EOS 835) was also employed to detect the presence of gaseous ammonia. Gas sensing tests were done to verify the sensitivity of the matrix to ammonia. Microstructural analysis was carried out by means of scanning and transmission electron microscopy. It was found that urease retained its activity inside molybdenum trioxide sol-gels that are sensitive to ammonia. These hybrid nanoporous composites are useful in the field of biosensors and fuel cells.

Oxidation Characteristics of Various Nickel Composite Coated on Ferritic Stainless Steel

2013 ◽  
Vol 789 ◽  
pp. 455-459
Author(s):  
Asep Ridwan Setiawan ◽  
Raden Dadan Ramdan ◽  
Budi Prawara ◽  
Steven Steven ◽  
Rochim Suratman
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Sol Gel ◽  
Substrate Material ◽  
Stainless Steel Surface ◽  
Service Temperature ◽  
X Ray Diffraction ◽  
Composite Layers ◽  
Oxidation Characteristics ◽  
Before And After

The present works concerns in developing alternative interconnect material for solid oxide fuel cell (SOFC) application. For this purpose, ferritic stainless steel is used as the substrate material while various nickel composite layers were coated on the substrate in order to improve its oxidation resistance at SOFC application temperature. Nickel layers were deposited on ferritic stainless steel by high velocity oxy-fuel (HVOF) method. In order to create nickel-oxide layer, the coated samples is then heated at temperature of 950°C for 1 hour, wherease sol-gel coating was performed on the coated samples in order to create nickel manganese oxide spinnel composite layers. All samples were then oxidized at temperature 800°C for 8 hours, in order to evaluate their oxidation characteristics at SOFC service temperature. Before and after oxidation, x-ray diffraction (XRD) and scanning electron microscope (SEM) were performed to all samples. It was observed that coated samples effectively inhibit the formation of chromium oxide that normally occurs on stainless steel surface at SOFC service temperature.

Protective hybrid sol–gel coatings containing bioactive particles on surgical grade stainless steel: Surface characterization

2007 ◽  
Vol 253 (17) ◽  
pp. 7260-7264 ◽  
Author(s):  
Josefina Ballarre ◽  
Damián A. López ◽  
Wido H. Schreiner ◽  
Alicia Durán ◽  
Silvia M. Ceré
Keyword(s):  
Stainless Steel ◽  
Surface Characterization ◽  
Steel Surface ◽  
Sol Gel ◽  
Stainless Steel Surface
Sign in / Sign up

Export Citation Format

Share Document