title: Control of surface topography in biomimetic calcium phosphate coatings.
abstract: The behavior of cells responsible for bone formation, osseointegration, and bone bonding in vivo are governed by both the surface chemistry and topography of scaffold matrices. Bone-like apatite coatings represent a promising method to improve the osteoconductivity and bonding of synthetic scaffold materials to mineralized tissues for regenerative procedures in orthopedics and dentistry. Polycaprolactone (PCL) films were coated with calcium phosphates (CaP) by incubation in simulated body fluid (SBF). We investigated the effect of SBF ion concentration and soaking time on the surface properties of the resulting apatite coatings. CaP coatings were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and energy dispersive X-ray spectrometry (EDX). Young's modulus (E(s)) was determined by nanoindentation, and surface roughness was assessed by atomic force microscopy (AFM) and mechanical stylus profilometry. CaP such as carbonate-substituted apatite were deposited onto PCL films. SEM and AFM images of the apatite coatings revealed an increase in topographical complexity and surface roughness with increasing ion concentration of SBF solutions. Young's moduli (E(s)) of various CaP coatings were not significantly different, regardless of the CaP phase or surface roughness. Thus, SBF with high ion concentrations may be used to coat synthetic polymers with CaP layers of different surface topography and roughness to improve the osteoconductivity and bone-bonding ability of the scaffold.
authors.affiliation: Department of Chemical and Biochemical Engineering, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Costa
authors.forename: Bedilu A
authors.initials: BA
authors.lastname: Allo
authors.forename: Robert
authors.initials: R
authors.lastname: Klassen
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Hutter
authors.forename: S Jeffrey
authors.initials: SJ
authors.lastname: Dixon
authors.forename: Amin S
authors.initials: AS
authors.lastname: Rizkalla
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D032701:Biomimetics / Q000379:methods*; D002130:Calcium Phosphates / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D055119:Elastic Modulus; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D011091:Polyesters; C016240:polycaprolactone; C020243:calcium phosphate