Synthesis and characterization of glycyrrhizin-decorated graphene oxide for hepatocyte-targeted delivery

The present work was to investigate graphene oxide (GO) decorated with glycyrrhizin (GL) which were conjugated via strong hydrogen-bonding interaction as a new hepatocyte-targeted delivery vehicle. The hydrogen-bonding interaction, simplified as a non-covalent type of functionalization, enables high drug loading and subsequent controlled release of the drug. An effective loading of GL on GO as high as 5.19 mg/mg was obtained at initial GL concentration of 0.6 mg/mL. The release of GL on GO showed strong pH dependence and the extent of release at pH 5.5 and 7.4 is 58.4% and 17.6% over 30 h in vitro respectively. The results show that the GO-GL complex seems to be a very promising vehicle for loading of drugs under neutral conditions and releasing under acidic environment. Furthermore, GO-GL can be obtained under mild conditions without addition of any organic solvents and surfactants, which is very suitable for pharmaceutical applications as a promising hepatocyte-targeted delivery carrier.