title: The release of nickel from nickel-titanium (NiTi) is strongly reduced by a sub-micrometer thin layer of calcium phosphate deposited by rf-magnetron sputtering.
abstract: Thin calcium phosphate coatings were deposited on NiTi substrates (plates) by rf-magnetron sputtering. The release of nickel upon immersion in water or in saline solution (0.9% NaCl in water) was measured by atomic absorption spectroscopy (AAS) for 42 days. The coating was analyzed before and after immersion by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). After an initial burst during the first 7 days that was observed for all samples, the rate of nickel release decreased 0.4-0.5 ng cm(-2) d(-1) for a 0.5 mum-thick calcium phosphate coating (deposited at 290 W). This was much less than the release from uncoated NiTi (3.4-4.4 ng cm(-2) d(-1)). Notably, the nickel release rate was not significantly different in pure water and in aqueous saline solution.
authors.affiliation: Department of Theoretical and Experimental Physics, Tomsk Polytechnic University, Tomsk, Russia. surmenev@tpu.ru
authors.forename: R A
authors.initials: RA
authors.lastname: Surmenev
authors.forename: M A
authors.initials: MA
authors.lastname: Ryabtseva
authors.forename: E V
authors.initials: EV
authors.lastname: Shesterikov
authors.forename: V F
authors.initials: VF
authors.lastname: Pichugin
authors.forename: T
authors.initials: T
authors.lastname: Peitsch
authors.forename: M
authors.initials: M
authors.lastname: Epple
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry* / Q000494:pharmacology; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000493:pharmacokinetics*; D004595:Electroplating / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry / Q000493:pharmacokinetics*; D010316:Particle Size; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties / Q000187:drug effects; D014025:Titanium / Q000737:chemistry / Q000493:pharmacokinetics*; D014867:Water / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D014961:X-Ray Diffraction
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D014867:Water; C040654:titanium nickelide; D012965:Sodium Chloride; D009532:Nickel; C020243:calcium phosphate; D014025:Titanium