Fabrication of the Silicate Containing CaTiO₃ Film with Hydrophilic and Smooth Surface on Titanium to Improve Osteoconductivity

Abstract

It has been reported that hydrophilicity and hydrophobicity of implants influenced the bioactivity. However, it is hard to maintain the hydrophilicity in case of being stored in air. So it is critical to find a way to maintain implants' hydrophilicity. In general, silicate has been known to contribute the hydrophilicity. In this study, the silicate containing CaTiO 3 films have been prepared on Ti substrates by two-step treatment for biomaterial applications. The hydrophilicity, osteoconductivity and protein adsorption of treated specimens have been investigated. The 1st step treatment for Ti is to form TiO 2 as precursors, either by anodizing in sulfuric acid solution at 298 K, liquid phase oxidation in nitric acid solution with hydrogen peroxide at 353 K, or thermal oxidation at 673 K in air. Hydrothermal treatment in silicate containing alkaline solution is the 2nd step to convert TiO 2 to silicate containing CaTiO 3 films. The SEM, XRD, XPS, WCA (water contact angle) investigations and protein adsorption measurements have been carried out to characterize the surface properties. This surface maintained 10 deg. in WCA after 7 d exposure in air, while the specimen without silicate has WCA of more than 40 deg. The osteoconductivity is evaluated based on the contact ratio of formed hard tissue on the implanted specimens after 14 d implantation in rats' tibia at in vivo test. The as-prepared film not only has exhibited smooth and superhydrophilic surface, but also has achieved high osteoconductivity and great protein adsorption capacity.

Metallic Implant Surface Activation through Electrospinning Coating of Nanocomposite Fiber for Bone Regeneration

“…Because of their exceptional mechanical qualities, superior biocompatibility, and excellent corrosion resistance, commercially pure titanium and Ti-based alloys have been widely employed in hard tissue replacement metallic implants, especially in the orthopedic and dental professions [5][6][7][8]. Among the most recommended reasons for boneimplant failure are stress shielding, inadequate osseointegration, and a high potential for bacterial infections.…”

Titanium alloys with varying surface micro-area potential differences have antibacterial abilities and a favorable cellular response

“…In order to accelerate and achieve earlier and better osseointegration, Ti and Ti alloys with different surfaces micro-scale topographies produced by acid-etching, sandblasting and anodization have been developed and it has been proved that micro-scale topography could promote the adhesion, differentiation, extracellular matrix formation and mineralization of osteoblasts [16][17][18]. Other studies also showed that surface roughness and hydrophilicity could obviously in uence osteoconductivity of Ti by altering protein adsorption and cell adhesion after implantation [19]. Recently, it was reported that the charge properties and the charge density of the material surface could affect the cell growth and cell reaction, because of the electrostatic interaction between a positively charged material surface and a negatively charged cell membrane.…”