Evaluation of the Adhesion of Ultra-Thin Teflon-Like Films Deposited by Plasma on 316L Stainless Steel for Long-Term Stable Drug-Eluting Stents

Metallic intravascular stents are medical devices commonly made of 316L stainless steel or nitinol used to scaffold a biological lumen, most often diseased arteries, after balloon angioplasty. Stenting procedures reduce the risk of restenosis, but do not eliminate it completely. Indeed, restenosis remains the principal cause of clinical complications, leading to up to 30 % of failure after 3 months of implantation. During the last few years, several works have been focused on the development of an appropriate coating able to act as a carrier for specific anti-restenosis drugs. Moreover, this coating would act as an anti-corrosive barrier, thus inhibiting the release of potentially toxic ions. Actually, the main challenges in stent coatings are to synthesize a biocompatible polymer coating resistant to blood flow, wall shear stress and tensile force after the stent deployment which results in a permanent strain of up to 25%. The adhesion and chemical resistance after deployment are critical properties to investigate for the improvement of the long-term reliability of polymer coated stent. The aim of this study was to evaluate the effect of a 25% equivalent plastic deformation on chemical, mechanical and adhesion properties of Teflon-like films deposited on 316L stainless steel. These properties were studied by chemical spectroscopy and atomic force microscopy. Teflon-like films were deposited by pulsed plasma glow discharges on flat electropolished 316L stainless steel. An original method has been developed to induce the deformation, and preliminary results have showed that the 12 nm thick Teflon-like films successfully resist to deformations of up to 25%.

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Polysaccharides Grafting on Fluorocarbon Films Deposited by Plasma on 316L Stainless Steel for Long Term Stable Stent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.409.164 ◽

2011 ◽

Vol 409 ◽

pp. 164-169

Author(s):

Eléonore Michel ◽

P. Chevallier ◽

Amélie Barrère ◽

Didier Letourneur ◽

D. Mantovani

Keyword(s):

Stainless Steel ◽

Periodate Oxidation ◽

Stent Deployment ◽

Fluorocarbon Films ◽

Stent Restenosis ◽

Clinical Complications ◽

Intravascular Stents ◽

Steel Substrates ◽

Fluorocarbon Film

Metallic intravascular stents are medical scaffolds commonly used to heal diseased arteries and to restore blood flow in vessels after a balloon angioplasty. Although clinical complications occurs (mainly in-stent-restenosis, representing 30-40% of cases within six months after angioplasty), this clinical procedure reduces the risk of restenosis. In order to improve the long-term clinical performances of stents, different coatings, bioactives or not, are investigated. However, the adhesion of the coating within the substrate is often weak and delamination after stent deployment could be observed. Therefore, our approach was to consider a plasma fluorocarbon film deposit on stainless steel substrates, improving adhesion and providing protection against the stent corrosion, as a carrier for the subsequent grafting of a polysaccharide (dextran). Indeed, a copolymer made of dextran and metacrylate has already demonstrated interesting results toward cell proliferation and appropriate mechanical properties regarding stent deployment. Hence, the aim of this project is to covalently graft the copolymer of dextran-methacrylate to plasma-aminated fluorocarbon film. In this study, dextrans were functionalized in order to conjugate them to amino groups. Two different ways of functionalization were investigated: by carboxylmethylation reaction and by periodate oxidation. Characterizations were performed by FTIR, for organic syntheses and by XPS for the subsequent grafting on the surface. Coatings topography and stability were also investigated. Preliminary results suggest the use of polysaccharides grafted by plasma on fluorocarbon films to provide a stable stent surface.

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Characterization of PTFE Film on 316L Stainless Steel Deposited through Spin Coating and Its Anticorrosion Performance in Multi Acidic Mediums

Materials ◽

10.3390/ma13020388 ◽

2020 ◽

Vol 13 (2) ◽

pp. 388 ◽

Cited By ~ 1

Author(s):

Waseem Akram ◽

Amer Farhan Rafique ◽

Nabeel Maqsood ◽

Afzal Khan ◽

Saeed Badshah ◽

...

Keyword(s):

Stainless Steel ◽

Spin Coating ◽

316L Stainless Steel ◽

Electrochemical Corrosion ◽

Hardness Test ◽

Coated Sample ◽

Uncoated Sample ◽

Ptfe Film ◽

Adhesion Properties ◽

Coated Substrate

Polytetrafluoroethylene (PTFE) was coated on 316L stainless steel (SS) substrate through a spin coating technique to enhance its corrosion resistance properties in hydrochloric acid (HCl) and nitric acid (HNO3) medium. Scanning electron microscopy (SEM) revealed the morphology of the coated and uncoated substrates and showed a uniform and crack-free PTFE coating on 316L SS substrate, while a damaged surface with thick corrosive layers was observed after the electrochemical test on the uncoated sample. However, an increased concentration of HCl and HNO3 slightly affected the surface morphology by covering the corrosive pits. An atomic force microscope (AFM) showed that the average surface roughness on 316L SS and PTFE coating was 26.3 nm and 24.1 nm, respectively. Energy dispersive X-ray spectroscopy (EDS) was used for the compositional analysis, which confirmed the presence of PTFE coating. The micro Vickers hardness test was used to estimate the hardness of 316L SS and PTFE-coated substrate, while the scratch test was used to study the adhesion properties of PTFE coating on 316L SS. The anticorrosion measurements of 316L SS and PTFE-coated substrates were made in various HCl and HNO3 solutions by using the electrochemical corrosion test. A comparison of the corrosion performance of PTFE-coated substrate with that of bare 316L SS substrate in HCl medium showed a protection efficiency (PE) of 96.7%, and in the case of HNO3 medium, the PE was 99.02%, by slightly shifting the corrosion potential of the coated sample towards the anodic direction.

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Enhancement of antimicrobial and long-term biostability of the zinc-incorporated hydroxyapatite coated 316L stainless steel implant for biomedical application

Ceramics International ◽

10.1016/j.ceramint.2012.12.019 ◽

2013 ◽

Vol 39 (5) ◽

pp. 5205-5212 ◽

Cited By ~ 33

Author(s):

S. Sutha ◽

G. Karunakaran ◽

V. Rajendran

Keyword(s):

Stainless Steel ◽

316L Stainless Steel ◽

Biomedical Application ◽

Stainless Steel Implant

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Evaluation of the Corrosion Protection of Ultra-Thin Plasma Fluorocarbon Film Deposited on 316L Stainless Steel for Long-Term Stable Stents

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.10 ◽

2010 ◽

Vol 638-642 ◽

pp. 10-15 ◽

Cited By ~ 2

Author(s):

Maryse Touzin ◽

P. Chevallier ◽

Stéphane Turgeon ◽

Paula Horny ◽

D. Mantovani

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

316L Stainless Steel ◽

Localized Corrosion ◽

Clinical Test ◽

General Corrosion ◽

Complication Rates ◽

Metallic Stent ◽

Intravascular Stents ◽

Fluorocarbon Film

Commonly made of 316L stainless steel and nitinol, metallic intravascular stents are medical devices used to scaffold a biological lumen, most often diseased arteries. While stenting procedures reduce the risk of restenosis, they do not eliminate it completely. Furthermore, other common complications observed are thrombosis, inflammation and corrosion of the stents. The corrosion of the device is induced by blood flow which provokes a degradation of its mechanical properties and leads to a high risk of release of potentially toxic metallic compounds, such as nickel-based oxides and metal ions. To lower these clinical complication rates and to prevent the corrosion of the metallic stent structure, coated stents have been developed during the last decade. Indeed, the coating is expected to improve the surface biocompatibility and corrosion resistance without compromising the stainless steel mechanical properties required for the stent implantation. The Food and Drug Administration (FDA) has already provided guidance on a series of non-clinical test protocols, methods and reports to evaluate the safety and effectiveness of intravascular stents. Properties such as the stability, durability, and adhesion of a stent coating, prior and after deployment, must be clearly assessed to demonstrate its efficiency. This study wants to evaluate the effectiveness against general and local corrosion of an ultra-thin fluorocarbon film deposited by plasma on pre-treated stainless steel. Cyclic polarization tests were used to measure the coating capacity to protect the substrate from localized corrosion and Tafel plot corrosion measurements were used to evaluate the general corrosion behaviour of uncoated and coated, flat and deformed samples.

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Long-term field exposure corrosion behavior investigation of 316L stainless steel in the deep sea environment

Ocean Engineering ◽

10.1016/j.oceaneng.2019.106405 ◽

2019 ◽

Vol 189 ◽

pp. 106405 ◽

Cited By ~ 2

Author(s):

Tigang Duan ◽

Wenshan Peng ◽

Kangkang Ding ◽

Weimin Guo ◽

Jian Hou ◽

...

Keyword(s):

Stainless Steel ◽

Corrosion Behavior ◽

Deep Sea ◽

316L Stainless Steel ◽

Field Exposure ◽

Term Field

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Applicability of Repassivation Potential for Long-Term Prediction of Localized Corrosion of Alloy 825 and Type 316L Stainless Steel

CORROSION ◽

10.5006/1.3316014 ◽

1993 ◽

Vol 49 (11) ◽

pp. 885-894 ◽

Cited By ~ 60

Author(s):

N. Sridhar ◽

G. A. Cragnolino

Keyword(s):

Stainless Steel ◽

316L Stainless Steel ◽

Localized Corrosion ◽

Term Prediction ◽

Repassivation Potential ◽

Type 316L ◽

Long Term Prediction ◽

Type 316L Stainless Steel

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The covalent immobilization of heparin to pulsed-plasma polymeric allylamine films on 316L stainless steel and the resulting effects on hemocompatibility

Biomaterials ◽

10.1016/j.biomaterials.2009.11.091 ◽

2010 ◽

Vol 31 (8) ◽

pp. 2072-2083 ◽

Cited By ~ 154

Author(s):

Zhilu Yang ◽

Jin Wang ◽

Rifang Luo ◽

Manfred F. Maitz ◽

Fengjuan Jing ◽

...

Keyword(s):

Stainless Steel ◽

316L Stainless Steel ◽

Covalent Immobilization ◽

Pulsed Plasma

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Effects of Ni and Ni + Co Additions in P/M Stainless Steel 316L on Sigma Phase and Oxide Formations after Long Term Heating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.894.227 ◽

2014 ◽

Vol 894 ◽

pp. 227-233 ◽

Cited By ~ 1

Author(s):

Panyawat Wangyao ◽

Nantawan Pichaiwong ◽

Visuttipitukul Patama ◽

Nutthita Chuankrerkkul ◽

Jirutthitikalpongsri Hirunyagird

Keyword(s):

Stainless Steel ◽

Sigma Phase ◽

316L Stainless Steel ◽

Hydrogen Atmosphere ◽

Microstructural Stability ◽

Stainless Steel 316L ◽

Single Action ◽

The Matrix ◽

Ni Additions

The effects of various Nickel and Nickel with Cobalt additions in P/M 316L stainless steel on sigma phase and oxide formations were investigated. Various powder mixtures of P/M316L with Ni and both Ni + Co powders as 1, 2, 3 and 4% by wt.%, were compacted using single action press under 498 MPa and sintered at 1300 °C for 30 minutes in hydrogen atmosphere. Then specimens were exposed at temperature of 800 °C and 900 °C for 25, 50, 75 and 100 hours in order to investigate the microstructural stability. It was found that specimens with both Co and Ni additions could reduce amount of sigma phase formation especially at heating of 900 °C. After all heat treatments, oxide scales had grown in closed pores during heating, therefore, the amount and size of internal porosity were decreased. It was also observed that the amount and size of porosity of heated specimens still have the same tendency as sintered specimens. The oxide scale in the matrix is mainly composed of Fe3O4 and Cr2O3 in the closed pores.

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