Analysis of the Calcium Phosphate-Based Hybrid Layer Formed on a Ti-6Al-7Nb Alloy to Enhance the Ossseointegration Process

Abstract

This paper reports on hybrid, bioactive ceramic Ca-P-based coating formation on a Ti-6Al-7Nb alloy substrate to enhance the osseointegration process. The Ti alloy was anodized in a Ca3(PO4)2 suspension and then the additional layer was formed by the sol-gel technique to obtain a mixture of the calcium phosphate compounds. The oxide layer was porous and additional ceramic particles were formed after sol-gel treatment (scanning electron microscopy analysis coupled with energy-dispersive x-ray spectroscopy). The ceramic particles were formed on some parts of the oxide layer and did not completely fill the pores. The layer thickness of the anodized Ti alloy was comprised between 3.01 and 5.03 µm and increased to 7.52–12.30 µm after the formation of an additional layer. Post-treatment of the anodized Ti alloys caused a decrease in surface roughness, and the layer became strongly hydrophilic. Crystalline phase analysis (X-ray diffraction, XRD) showed that the hybrid layer was composed of TiO2 (anatase), Ca3(PO4)2, Ca10(PO4)6(OH)2 and a partially amorphous phase; thus, the layer was also analyzed by Raman spectroscopy. The hybrid layer showed worse adhesion to the substrate than the anodized layer only; however, the coating was not brittle, and the first delamination of the layer was determined at 1.84 ± 0.11 N during scratch-test measurement. The hybrid coating was favorable for collagen type I and lactoferrin adsorption, strongly influencing the proliferation of osteoblast-like MG-63 cells. The coatings were cytocompatible and may find applications in formation of the functional layers on long-term implants’ surface after.

Bisphosphonate-incorporated coatings for orthopedic implants functionalization

“…The condition of drug release depends on a combination of factors, such as the drug properties and the method and materials of loading BPs. Thus, the multivalent interactions between BPs and supported materials have paramount importance for osseointegration [ 90 ]. To understand the interactions, it is essential to have detailed knowledge on the mechanisms of constructing BP-coated implants.…”

Nitrilotriacetic Acid Improves Plasma Electrolytic Oxidation of Titanium for Biomedical Applications

“…Section with EDX Mapping. The thickness and structure of the PEO coating layers were investigated using the crosssectional method previously described 6 with modifications. The PEOcoated Ti specimens were embedded in epoxy resin at room temperature.…”

“…Plasma electrolytic oxidation (PEO) is a method of choice to supply artificial dental/bone implants with bioactive surfaces to improve postoperative healing and long-term stability. , Indeed, PEO-generated surfaces have been shown to increase osseointegration , and possess antibacterial properties. , Moreover, PEO surface layers can increase the corrosion of implants, especially with biodegradable materials such as Mg alloys . PEO processing could be especially useful for implants in patients with low bone mineral density (osteoporosis) and other medical conditions .…”

Incorporation of inorganic elements onto titanium-based implant surfaces by one-step plasma electrolytic oxidation: an efficient method to enhance osteogenesis

“…In recent years, the combination of plasma electrolytic oxidation and other surface modification technologies attracts researchers’ attention in the implant modification field as well, for instance, combining hydrothermal treatments, steam-hydrothermal treatment, air-plasma treatment, and sol–gel treatment with plasma electrolytic oxidation. 47–50…”