Abstract

In the present study, a novel chitosan-functionalized graphene oxide decorated with glycidyl methacrylate (GO-CS-GMA) was synthesized and combined with nanohydroxyapatite particles (nHAp) to produce a novel hybrid synthetic natural material as a reinforcing phase for dental and biomedical purposes. In this process, the graphene oxide converted to GO-COCl, then reacted with chitosan (CS) to prepare GO-CS and final reaction of GO-CS with glycidyl methacrylate (GMA) gave methacrylate functionalized GO-CS-GMA. In another process, an alkyl bromide derivative of nanohydroxyapatite (nHAp-Br, radical initiator) was made from reaction of nHAP with 2-bromoisobutyryl bromide. Finally, atom transfer radical polymerization (ATRP) was used to the grafting of GO-CS-GMA onto nHAp surface to give nanohybrid compounds that were utilized in the nanocomposite formulation. The structure, thermal stability, and mechanical properties of the nanocomposites were investigated by FTIR, XRD, CHN, FE-SEM, and TGA. The thermal stability of the final composite was higher than its precursor nHAp and GO-CS-GMA. A synergistic effect of graphene oxide, chitosan, and glycidyl methacrylate on reinforcing hydroxyapatite has been observed. The resulting nanocomposite revealed around 56 and 20 increases in compressive and flexural strength, respectively, in comparison with hydroxyapatite. In addition, both compressive and flexural strengths of new composites were improved in comparison with the conventional composites which are made from barium glass fillers. Cellular studies using human alveolar basal epithelial cells (A549 cell line) suggest that remarkable biocompatibility is shown by nHAp-g-GO-CS-GMA, which makes it an encouraging material for biomedical applications.