Production and characterization of hydroxyapatite-graphane oxide-chitosan scaffold for bone tissue engineering application

Abstract

Bone tissue engineering is a strategy to regenerate diseased or damaged bone tissues by providing the biological microenvironment with the use of appropriate scaffolds that can mimic the native extracellular matrix for bone tissue cells. In the literature, there are many studies performed on this subject, but, no studies have been conducted on the investigation of the production of three-component scaffold, which composed of hydroxyapatite (HAp) derived from eggshells, graphene oxide (GO) and chitosan (CS), by using the supercritical gel drying method, and on the examination of the possible toxicity effects of GO additions. In the present study, HAp derived from the eggshells, which is used for the production of three-component scaffolds composed of HAp-GO-CS, was synthesized by using the precipitation method. Improved Hummer method was used for the synthesis of GO, which was used as an osteoconductive agent. The mixtures of scaffolds were prepared by mixing the solutions of HAp, GO and CS, and these mixtures were frozen after molded. Then, the water-acetone substitution procedure was applied to the frozen samples, the supercritical gel drying was performed to produce scaffolds. Three-component scaffolds, produced at different GO ratios to examine the toxic effect of GO, were characterized by FTIR, XRD, SEM, TEM, EDS, BET and TG/DTA analyses. For the evaluation of the mechanical properties of the produced scaffolds, Universal Instron Mechanical Test System was used. The scaffolds were subjected to MTT testing for cytotoxicity analysis. MTT analysis showed that the use of GO ratio more than 1% (w/w) had a toxic effect on MC3T3-E1 cells. According to the characterization studies performed, it was determined that HAp-GO(1%)CS three-component scaffold including 1% (w/w) of GO ratio had three-dimensional porous structure, highest cell viability and reasonable mechanical properties. According to the findings, it was concluded that HAp-GO(1%)-CS based composite is a promising scaffold, and could be used for the applications in bone tissue engineering.