Silane Adhesion Promoters for Polymeric Coatings

Author(s):  
Edwin P. Plueddemann
2015 ◽  
Vol 1 (1) ◽  
pp. 493-497 ◽  
Author(s):  
V. Radun ◽  
R. P. von Metzen ◽  
T. Stieglitz ◽  
V. Bucher ◽  
A. Stett

AbstractDelamination of thin film polymeric coatings from metallization layers is a common cause of failure in biomedical implants. To address the problem, different adhesion promotion techniques can be applied which include surface pre-treatment with oxygen and argon plasma and the use of different adhesion promoters. In this paper the applicability of titanium (Ti), silicon oxide (SiOx), diamond-like carbon (DLC), tetramethylsilane (TMS) and aluminium oxide (AlOx) as adhesion promoters is evaluated. A cross cut, peel and scratch test are used to qualify and quantify the adhesion before and after storage in phosphate buffered saline (PBS) for 48 hours at a temperature of 37 °C. Promising results could be achieved by a combination of Ti and DLC as well as by AlOx.


2018 ◽  
Vol 92 (4) ◽  
pp. 119-131 ◽  
Author(s):  
A.V. Buketov ◽  
◽  
M.V. Brailo ◽  
D.P. Stukhlyak ◽  
S.V. Yakushchenko ◽  
...  
Keyword(s):  

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1026
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Matthew T. Geib ◽  
M. Selim Ünlü

The importance of microarrays in diagnostics and medicine has drastically increased in the last few years. Nevertheless, the efficiency of a microarray-based assay intrinsically depends on the density and functionality of the biorecognition elements immobilized onto each sensor spot. Recently, researchers have put effort into developing new functionalization strategies and technologies which provide efficient immobilization and stability of any sort of molecule. Here, we present an overview of the most widely used methods of surface functionalization of microarray substrates, as well as the most recent advances in the field, and compare their performance in terms of optimal immobilization of the bioreceptor molecules. We focus on label-free microarrays and, in particular, we aim to describe the impact of surface chemistry on two types of microarray-based sensors: microarrays for single particle imaging and for label-free measurements of binding kinetics. Both protein and DNA microarrays are taken into consideration, and the effect of different polymeric coatings on the molecules’ functionalities is critically analyzed.


Author(s):  
Monisha Baby ◽  
Vijayalakshmi K. Periya ◽  
Bhuvaneshwari Soundiraraju ◽  
Nisha Balachandran ◽  
Suchithra Cheriyan ◽  
...  

2020 ◽  
Vol 92 (8) ◽  
pp. 1329-1340
Author(s):  
A. G. Kolmakov ◽  
A. S. Baikin ◽  
S. V. Gudkov ◽  
K. N. Belosludtsev ◽  
E. O. Nasakina ◽  
...  

AbstractThe paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2551
Author(s):  
Wojciech Kajzer ◽  
Janusz Szewczenko ◽  
Anita Kajzer ◽  
Marcin Basiaga ◽  
Joanna Jaworska ◽  
...  

In this study, we aimed to determine the effect of long-term exposure to artificial urine on the physical properties of CoCrMo alloy with biodegradable heparin-releasing polymeric coatings. Variants of polymer coatings of poly(L,L-lactide-ɛ-caprolactone) (P(L,L-L/CL)) and poly(D,L-lactide-ɛ-caprolactone) (P(D,L-L/CL)) constituting the base for heparin-releasing (HEP) polyvinyl alcohol (PVA) coatings were analyzed. The coatings were applied by the dip-coating method. Heparin was used to counteract the incrustation process in the artificial urine. The study included tests of wettability, resistance to pitting and crevice corrosion, determination of the mass density of metal ions penetrating into the artificial urine, and the kinetics of heparin release. In addition, microscopic observations of surface roughness and adhesion to the metal substrate were performed. Electrolytically polished CoCrMo samples (as a reference level) and samples with polymer coatings were used for the tests. The tests were conducted on samples in the initial state and after 30, 60, and 90 days of exposure to artificial urine. The analysis of the test results shows that the polymer coatings contribute by improving the resistance of the metal substrate to pitting and crevice corrosion in the initial state and reducing (as compared with the metal substrate) the mass density of metal ion release into the artificial urine. Moreover, the PVA + HEP coating, regardless of the base polymer coatings used, contributes to a reduction in the incrustation process in the first 30 days of exposure to the artificial urine.


1995 ◽  
Vol 73 (9) ◽  
pp. 1427-1435 ◽  
Author(s):  
Zhiping Deng ◽  
David C. Stone ◽  
Michael Thompson

Poly N-(2-cyanoethyl)pyrrole films have been synthesized by electrochemical polymerization and characterized by cyclic voltammetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Polymeric coatings prepared on the surface of a thickness-shear-mode acoustic wave sensor have been used to examine response selectivity to a number of gas-phase probe molecules. The responses of the poly N-(2-cyanoethyl)pyrrole based sensor are compared with the parent polypyrrole device and rationalized in terms of the molecular interactions between probes and polymer films. The polar cyano functionality enhances interactions with analytes such as acetonitrile. Keywords: gas sensor, thickness-shear-mode acoustic wave sensor, poly N-(2-cyanoethyl)pyrrole film, polypyrrole film, conducting polymer.


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