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.

Comparative study of bioactivity of collagen scaffolds coated with graphene oxide and reduced graphene oxide

“…The interfacial morphology of cells strongly affects the induction of cell reactions. 34,35 Many investigators have demonstrated that nano-and micro-scale structures in bio-based materials provide advantages for tissue engineering processes. 36,37 Thus, nano-modification of RGO similarly provides advantages, such as porosity and surface structure, for tissue engineering of different cell types and of multicellular organisms.…”

Biomedical applications of nanotechnology

“…This methodology allows the formation of continuous CaP coatings with controlled surface topography (Costa et al 2012), but it can require long exposure times (Tas 2014). Simulated body fluid (SBF) is one of the most frequently used physiological solution (Kokubo et al 1990;Cüneyt Tas 2000).…”

Carboxymethyl cellulose/silica hybrids as templates for calcium phosphate biomimetic mineralization

“…The characteristic peaks of this apatite form located at 22.9, 31.85, 39.2, 42.1 and 46.81 which can be indexed as the (1 1 1), (1 2 1), (1 2 2), (3 1 1) and (2 2 2) planes of HA, respectively. In most cases of calcium-phosphate formation, amorphous calcium phosphate was firstly formed as non-crystalline form, which have strong tendency to transform into thermodynamically stable crystalline apatite by dissolution and recrystalization [34,35].…”

“…5. These types of spherical globules, which exhibit no distinct surface features, are normal for amorphous calcium phosphate [34] which can be converted, under hydrolysis-conversion process, to other crystalline phases [34,35].…”