Increased osteoblast adhesion on titanium‐coated hydroxylapatite that forms CaTiO₃

Abstract

CaTiO(3) is a strong candidate to form at the interface between hydroxylapatite (HA) and titanium implants during many coating procedures. However, few studies have compared the cytocompatibility properties of CaTiO(3) to HA pertinent for bone-cell function. For this reason, the objective of the present in vitro study was to determine the ability of bone-forming cells (osteoblasts) to adhere on titanium coated with HA that resulted in the formation of CaTiO(3). To accomplish the formation of CaTiO(3), titanium was coated on HA discs and annealed either under air or a N(2)+H(2) environment. Materials were characterized by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), and atomic force microscopy (AFM). These characterization techniques demonstrated the formation of a nanometer rough CaTiO(3) layer as a consequence of interactions between HA and titanium during coating conditions. Results from cytocompatibility tests revealed increased osteoblast adhesion on materials that contained CaTiO(3) compared to both pure HA and uncoated titanium. The greatest osteoblast adhesion was observed on titanium-coated HA annealed under air conditions. Because adhesion is a crucial prerequisite to subsequent functions of osteoblasts (such as the deposition of calcium containing mineral), the present in vitro results imply that orthopedic coatings that form CaTiO(3) could increase osseointegration with juxtaposed bone needed for increased implant efficacy.

The effect of surface treatment on the surface texture and contact angle of electrochemically deposited hydroxyapatite coating and on its interaction with bone-forming cells

“…The effect of roughness on cell attachment has been demonstrated before [23,36,43,50,58,61]. It was shown that the surface roughness must be within the scale of the cell to be perceived by the cell, and within this limit, rougher surfaces support the expression of a more differentiated osteoblastic phenotype based on increased alkaline phosphatase activity and osteocalcin production [50].…”

“…It was shown that the surface roughness must be within the scale of the cell to be perceived by the cell, and within this limit, rougher surfaces support the expression of a more differentiated osteoblastic phenotype based on increased alkaline phosphatase activity and osteocalcin production [50]. It was also reported that increased surface roughness, both at the micrometer and at the nanometer levels, without changes in surface chemistry, could promote functions of osteoblasts, leading to new bone synthesis [61]. Most studies, however, have expressed the roughness in terms of R a .…”

Osseoconductive and Corrosion-Inhibiting Plasma-Sprayed Calcium Phosphate Coatings for Metallic Medical Implants

“…Adhesion is overwhelmingly provided by mechanical clamping of coating particles to asperities of the roughened surface of the metallic substrate. Despite claims that a thin reaction layer of calcium dititanate (CaTi 2 O 5 ) or calcium titanate (perovskite, CaTiO 3 ) exists that will mediate adhesion [35][36][37], experimental evidence of such a reaction layer in as-sprayed coatings is scant or absent. Owing to its thinness, visualization by transmission electron microscopy even at high magnification [20] is hampered by its exiguity owing to the very short diffusion paths of Ca 2+ and Ti 4+ ions, respectively, that render any potential reaction zone extremely thin.…”

Surface Characteristics of Titanium Oxide Films Prepared by Micro-Arc Oxidation: Comparison of Direct Current Electrolysis and Pulse Electrolysis

“…20,21) The XRD peaks for HAp particles reveal that HAp particles are incorporated in the oxide film with no loss of crystallinity. Interestingly, CaTiO 3 , which is known to play a key role in the induction of bone-like apatite through the formation of Ti-OH, 19,22,23) was detected as clear peaks. CaTiO 3 is considered to be produced by Ca 2þ ions from HAp being incorporated in Ti substrates by the spark discharge energy.…”