title: Analysis of the effects of surface treatments on nickel release from nitinol wires and their impact on candidate gene expression in endothelial cells.
abstract: Nitinol has many applications in the medical device industry, however the large amount of nickel, a known allergen and carcinogen remains a serious concern. Studies have already shown that nickel ions induce the differential expression of a range of genes, including cell adhesion molecules. This study sought to determine the level of nickel ions released from nitinol wires that had been surface treated by etching and mechanically polishing or etching and pickling compared to untreated wires and determine the biological impact of the wires on human umbilical vein endothelial cells (HUVECs) at the transcriptional level by real-time PCR. The four different wire types were incubated in media and the amount of nickel eluted after 24, 48 and 72 h was determined. HUVECs were then cultured and incubated with the four different wire types for 24 h. Cells were harvested, RNA isolated and real-time PCR was carried out to measure the expression levels of ICAM-1, VCAM-1 and E-selectin, three known inflammatory mediators, compared to control cells. E-selectin, a marker of endothelial cell injury and activation was found to be significantly up-regulated in cells incubated with wires that released the highest amount of nickel ions. Nickel ions are released from nitinol wires with certain surface characteristics and these ions have a biological effect on HUVECs in vitro.
authors.affiliation: National Centre for Biomedical Engineering Science, National University of Ireland, Newcastle Rd., Galway, Ireland. emily.mclucas@nuigalway.ie
authors.forename: E
authors.initials: E
authors.lastname: McLucas
authors.forename: Y
authors.initials: Y
authors.lastname: Rochev
authors.forename: W M
authors.initials: WM
authors.lastname: Carroll
authors.forename: T J
authors.initials: TJ
authors.lastname: Smith
mesh_terms: D000497:Alloys / Q000737:chemistry / Q000378:metabolism*; D020099:Coated Materials, Biocompatible / Q000493:pharmacokinetics; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D007477:Ions / Q000493:pharmacokinetics; D008422:Materials Testing; D009532:Nickel / Q000493:pharmacokinetics*; D015607:Stents; D013499:Surface Properties / Q000187:drug effects; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D019040:E-Selectin; D007477:Ions; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; C013616:nitinol; D009532:Nickel