Carbon nanotube coating on titanium substrate modified with TiO2 nanotubes

A combination of carbon nanotubes (CNTs) and titanium (Ti) modified with TiO2 nanotubes (TiO2 NTs) was fulfilled with the aim of improving bioactivity of Ti implant. First, well-ordered TiO2 NTs were prepared by the electrochemical anodization of Ti in an ethylene glycol electrolyte containing 1 wt% NH4F and 10 wt% H2O at 20 V for 50 min, followed by annealing. Then, the carboxylated CNTs were coated onto the TiO2 NTs using electrophoretic deposition (EPD) technique. The growth of hydroxyapatite (HA) on the samples was investigated by soaking them in simulated body fluid (SBF). The result showed the CNTs-coated Ti with the modification of TiO2 NTs (CNTs-TiO2 NTs) was more efficient to induce HA formation than the CNTs-coated smooth Ti (CNTs-Ti). The vitro cell response was evaluated using osteoblast cells (MC3T3-E1). The good cell proliferation and strong cell adhesion could be obtained on the CNTs-TiO2 NTs. These results indicated that CNT coating on the Ti modified with TiO2 NTs could be potentially useful for the periodontal ligament combination on dental implants.