Skip to Content
Merck
  • Surface modification of Ni-Ti alloys for stent application after magnetoelectropolishing.

Surface modification of Ni-Ti alloys for stent application after magnetoelectropolishing.

Materials science & engineering. C, Materials for biological applications (2015-03-10)
Puneet Gill, Vishal Musaramthota, Norman Munroe, Amit Datye, Rupak Dua, Waseem Haider, Anthony McGoron, Ryszard Rokicki
ABSTRACT

The constant demand for new implant materials and the multidisciplinary design approaches for stent applications have expanded vastly over the past decade. The biocompatibility of these implant materials is a function of their surface characteristics such as morphology, surface chemistry, roughness, surface charge and wettability. These surface characteristics can directly influence the material's corrosion resistance and biological processes such as endothelialization. Surface morphology affects the thermodynamic stability of passivating oxides, which renders corrosion resistance to passivating alloys. Magnetoelectropolishing (MEP) is known to alter the morphology and composition of surface films, which assist in improving corrosion resistance of Nitinol alloys. This work aims at analyzing the surface characteristics of MEP Nitinol alloys by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The wettability of the alloys was determined by contact angle measurements and the mechanical properties were assessed by Nanoindentation. Improved mechanical properties were observed with the addition of alloying elements. Cyclic potentiodynamic polarization tests were performed to determine the corrosion susceptibility. Further, the alloys were tested for their cytotoxicity and cellular growth with endothelial cells. Improved corrosion resistance and cellular viability were observed with MEP surface treated alloys.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Sulforhodamine B, Dye content 75 %
Sigma-Aldrich
Streptomycin sulfate salt, powder, BioXtra, suitable for mouse embryo cell culture
Sigma-Aldrich
In Vitro Toxicology Assay Kit, Sulforhodamine B based
Sigma-Aldrich
Streptomycin sulfate salt, powder
Sigma-Aldrich
Streptomycin sulfate salt, powder, BioReagent, suitable for cell culture
Streptomycin sulfate, European Pharmacopoeia (EP) Reference Standard
Supelco
Streptomycin solution, ~1 mg/mL in 1 mM EDTA, analytical standard
Sigma-Aldrich
Sulforhodamine B sodium salt, Technical grade
Sigma-Aldrich
Sulforhodamine B sodium salt, powder, BioReagent, suitable for cell culture
Sigma-Aldrich
Streptomycin Ready Made Solution, 100 mg/mL in water