Preparation of Nanostructured Graphene Oxide and Its Application in Drug Loading and Sustained Release

Graphene oxide (GO) and its derivatives are considered as a promising drug carrier in tumor therapy due to their excellent biocompatibility. Here, a series of nanostructured GO with long-range ordered lamellar or hexagonal structure were prepared by lyotropic liquid crystals (LLCs) templating strategy and used as drug carriers. The nanostructure was verified via polarized-light optical microscopy (ROM), low angle X-ray diffraction (XRD) and transmission electron microscopy (TEM), which showed that the interlayer spacing or pore size was determined by the carbon chain length of templating molecular. 5-fluorouracil (5-Fu), doxorubicin (DOX) and docetaxel (DOC) which had gradually increased molecular size were chosen as model drugs, and the highly ordered nanochannels can be used as space for adsorption and diffusion of drug molecules. Ultraviolet spectrometer and simulated release test in vitro were used to determine drug loading capacity and drug release performance. The results showed that larger pore diameter/layer spacing was beneficial to the adsorption and diffusion of drug molecules, especially those with shorter molecule size. Besides, the water-solvable DOX exhibited fast release rate than the hydrophobic 5-Fu and DOC. The in vitro cytotoxicity assay demonstrated the good biocompatibility of both the pristine GO and the nanostructured GO.