Preparation and characterization of dithiol-modified graphene oxide nanosheets reinforced alginate nanocomposite as bone scaffold

Porous graphene oxide (GO) nanocomposite as scaffold has attracted increasing attention in bone tissue engineering recently. In this study, GO nanosheets was modified by 2,2'-(ethylenedioxy)-diethnethiol (EDDET), and dithiol-modified GO (DT-GO) nanosheets were obtained. The results confirmed that GO nanosheets were cross-linked by EDDET, meanwhile, the distance between GO layers reduced after modification. Next, DT-GO nanosheets were further incorporated into alginate hydrogels to fabricate DT-GO/alginate (DT-GA) nanocomposite as scaffold. The prepared DT-GA nanocomposite behaved the laminar network morphology with interconnected porous structure confirmed by SEM analysis. In addition, the DT-GA nanocomposite with the concentration of DT-GO nanosheets at 16.7% showed the highest porosity value and lowest compressive strength. Furthermore, the bone marrow derived mesenchymal stem cells (BMSCs) showed a good proliferation on DT-GA nanocomposite, demonstrated that prepared nanocomposite had a good cytocompatibility, which was identified by CCK-8 assay and fluorescent microscopy images. Lastly, ALP activity analysis certified that BMSCs seeded on DT-GA nanocomposite could differentiate into osteoblastic phenotype. Above results suggest that the dithiol-modified GO/alginate nanocomposite has the potential to be applied in bone tissue engineering.