Effects of a carbon nanotube-collagen coating on a titanium surface on osteoblast growth

Abstract

This study was performed to evaluate the effect of collagen-multi-walled carbon nanotubes (MWCNTs) composite coating deposited on titanium on osteoblast growth. Titanium samples coated with only collagen and MWCNTs were used as controls. Pure titanium was coated with collagen-MWCNTs composite coating with 5, 10 and 20μgcm−2 MWCNTs by dip coating method. Scanning probe microscopy, field emission scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy were used to ascertain the root mean squared roughness, structural and morphological features and, the interaction between the collagen and the MWCNTs, respectively. The biocompatibility of the collagen-MWCNTs composite coated Ti was assessed by MTT and ALP activity assays after culturing the cells for 2 and 5 days. The study reveals that root mean squared surface roughness of collagen-MWCNTs composite coated titanium is relatively higher than those of collagen and MWCNTs coated Ti. There is a strong interaction between the MWCNTs and the collagen, which is supported by the inferences made in FE-SEM and TEM studies and further confirmed by FT-IR spectra. Among all the specimens tested, cell proliferation is relatively higher on collagen-MWCNTs composite coated Ti specimen incorporated with 20μgcm−2 of MWCNTs (p<0.05) after 5 days of cell culture. Cell proliferation studies confirm the existence of a strong dependence of the extent of cell proliferation on the amount of MWCNTs incorporated in the composite; the higher the amount of MWCNTs, the greater the extent of cell proliferation. The higher surface roughness of collagen-MWCNTs composite coated Ti specimens is considered responsible for the relatively higher extent of cell proliferation. The MWCNTs incorporated in the composite could have also contributed to the cell viability and growth.