New dendrimer functionalized multi-walled carbon nanotube hybrids for bone tissue engineering

Abstract

Two types of multi-walled carbon nanotubes (MWCNTs) functionalized with dendrimer/hydroxyapatite (HAp) nanohybrids viz., MWCNTs-poly(propylene imine) generation 2 (G2)-HAp (MWCNTs-PPI(G2)/HAp) and MWCNTs-poly(propylene imine) generation 3 (G3)-HAp (MWCNTs-PPI(G3)/HAp) were prepared. Initially, pristine-MWCNTs were oxidized to form MWCNTs–COOH and to which PPI(G2) and PPI(G3) were functionalized separately to obtain MWCNTs-PPI(G2) & MWCNTs-PPI(G3) matrices. Nanostructured HAp was prepared by wet precipitation method and bonded to MWCNTs-PPI(G2) & MWCNTs-PPI(G3) matrices. The cross-linkages in carbon nanotube based nanohybrids (CNTs-nanohybrids) were observed by Fourier transform infrared spectroscopy. Surface morphology of the CNTs-nanohybrids and the weight percentage of HAp deposited onto the MWCNTs-PPI(G2 & G3) matrices were confirmed by field emission scanning electron microscopy and energy dispersive spectroscopy analyses. The average crystal size of HAp was calculated from the X-ray diffraction patterns using the Debye–Scherrer equation. The in vitro anticancer effect and cell viability of newly fabricated CNTs-nanohybrids were examined against human bone cancer cell line (human osteosarcoma (MG-63)) by means of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The results suggest that the prepared two types of MWCNTs-PPI(G2)/HAp & MWCNTs-PPI(G3)/HAp nanohybrids significantly enhanced the anticancer efficacy in cancer cells. The proposed hybrid materials on the basis of MWCNTs possess valuable scaffolds for both curative and preventative approaches in bone tissue engineering.