The synergistic effect of a hybrid graphene oxide-chitosan system and biomimetic mineralization on osteoblast functions

Graphene oxide and chitosan are promising materials for tissue regeneration. The present study explores a novel biomimetic mineralization route employing a graphene oxide (GO)-chitosan (CS) conjugate as a template material for the biomineralization of hydroxyapatite (HAP). Structural and morphological studies involving X-ray diffraction, Fourier transform infrared spectroscopy, and electron microscopy indicated that extensive mineralization occurred in the CS-GO conjugate system because of strong electrostatic interactions between the functional groups (carboxyl groups of GO and amino groups of CS) and calcium ions in the simulated body fluid (SBF). The combination of chitosan-graphene oxide conjugate and biomineralization was advantageous in favorably modulating cellular activity (osteoblast functions: cell attachment, proliferation, actin, vinculin and fibronectin expression). It is concluded that biomineralized hydroxyapatite in the HAP-CS-GO system induced homogeneous spatial osteoblastic cell growth and quantitatively (e. g. area) and qualitatively (e. g. mineral-to-matrix ratio) increased mineralization in relation to the HAP-GO system. The data underscore that covalent linkage of HAP to chitosan influences osteoblastic cell differentiation, mineralization, and cell growth. The proposed system and the revelation of fundamental insights merit consideration in tissue engineering.