Biomimetic Coating of Titanium Surface Using Bioactive Glass Nanoparticles

The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and characterize the deposited surface coat.

Amorphous bioglass nanoparticles < 20 nm in diameter were prepared using a modified sol-gel technique followed by a ball-milling process. The prepared nanoparticles were used to coat airborne particle-abraded titanium disks. The in vitro bioactivity of the bioglass nanopowder was confirmed using simulated body fluid. Coated surfaces were characterized in terms of microstructure, composition, thickness, phase structure, surface roughness, wettability, and tissue behavior in a rabbit model.

Bioglass nanoparticles showed apatite formation under a scanning electron microscope (SEM) after 5 days, confirming that bioactivity was enhanced with increasing degradation rate for up to 2 weeks. An optimized deposition technique and heat-treatment process produced a homogenous coating with a uniform thickness of 32 to 39 μm. Chemical analysis confirmed the presence of silicon and calcium on the coated disks. Amorphous coated surfaces exhibited porous nano/microroughness with microcracks and super-hydrophilicity. The interface of the coated disks with subcutaneous tissue revealed good tissue adhesion, high cellular activity, and rich vascularization, with multinucleated cells in the microenvironment surrounding the coat, as confirmed using histomorphometric analysis.

The results of this study show that it is feasible to coat titanium surfaces with bioactive glass nanoparticles with super-hydrophilicity and high biologic activity. These particles may promote the regenerative environment around dental implants.