Rough and Bioactive surfaces
Cp Ti surfaces treated to obtain a combination of an optimal random surface topography (in the micro and nanolevels) with a chemical modification of the naturally-formed titania layer have been proved bioactive. These rough and bioactive surfaces can nucleate and grow a homogeneous hydroxyapatite layer both in vitro and in vivo. They stimulate the osteoblasts differentiation and trigger a rapid bone formation that mechanically fixes implants under immediate-loading conditions.
Above: Enviromental Scanning Electron Microscopy (ESEM) images showing rough and bioactive surfaces that induce nucleation and growth of hydroxyaptite (X-Ray diffraction pattern shown) in vitro. ESEM image of an osteoblast on a rough and bioactive surface, which significantly induces osteoblast differentiation (ALP results shown). Histomorphometric results and histology showing a rapid integration of rough and bioactive surfaces under immediate-loading conditions. SEM image showing the apatite layer formed in vivo on these surfaces.
A simple process using silane chemistry has been proved specific, rapid, and reliable to covalently immobilize biomolecules on metallic surfaces. This methodology can be used to develop biofunctionalized implant surfaces with different or combined bioactivities. The biofunctional molecules can be proteins, growth factors, and synthetic peptides specifically designed to be attached to the surface and/or to self-assemble in order to form coatings with tailored properties. The bioactive properties of the molecules designed and used can be mineral growing and nucleation, osteoblast differentiation (bone regeneration), fibroblasts differentiation (biological sealing), antibiotic, biodegradable, drug delivering, etc.
Above: Schematics of the process used to biofunctionalize metallic surfaces. Different surface characterization (XPS, FT-IR, fluorescent labeling) results that prove specificity and reliability of the process. Osteoblasts-like cells on a cp Ti surface biofunctionalized with a RGD-containing recombinant elastin-like polymer.