Preparation Of Multi-Functionalized Graphene Oxide Gene Vector And Preliminary Studies On Targeting Therapy

With Gene therapy is a hot spot research for treating gene related diseasesespecially cancer in the past two decades. One of the key issues in gene therapy is todevelop a suitable gene drug delivery carrier which involved viral and non-viralvectors. The non-viral vectors have attracted considerable attention owing to its highsafety and efficiency in view of polymers, cationic lipids, nanoparticles and others. Inrecent years, the study of non-viral vectors has obtained great process. However, someproblems involving non-specificity to tumor sites, cytotoxicity and biocompatibility inphysiological environment have not been well solved. Therefore, the development ofpowerful nanocarrier is still the present significant challenges for gene therapy.Recently, graphene, an atom-thick sheets of carbon packed in a two-dimensionlayered structure with remarkable properties has been widely used in manyapplication fields of electrochemical devices, biomedicine and so on. Graphene oxide(GO), graphene’s water-soluble derivative has already attracted enormous interestsdue to its easy manufacture, well-dispersed in water and physiological environment,good colloidal stability and shown potential application in biological fields includingbiosensors, gene and drug delivery, as well as biological imaging in vitro and vivo.In this paper, a novel multi-functionalized GO-based gene vector was preparedfor targeting therapy of hepatocellular carcinoma successfully. TheGO-PEI-PEG-FA/si-Stat3gene vector was prepared by covalent modification of GOwith polyethyleneimine (PEI), Polyethylene glycol (PEG) and folic acid (FA) in turn,where after loading of si-Stat3via electrostatic interactions. In this gene vector, PEIwas used for controlling the transfection efficiency, PEG for improving the solubilityin physiological solutions, FA for targeting tumor therapy and si-Stat3was used for silencing of si-Stat3expression.We investigated the effects of the effective diameters and transfection efficiencyby changing the content of PEI in complex. It was found that with the content of PEIin complex the increase and the effective diameters reduce in turn until almostunchanged, along with the transfection efficiency of complex became higher. Thenthe results showed that the transfection efficiency is relatively high with the content ofPEI in complex at1：80without obvious cytotoxicity. At the same time, the stabilityof the complex in physiological conditions was improved. TheGO-PEI-PEG-FA/si-Stat3complex exhibited an excellent ability of silencing Stat3expression for targeting tumor hepatocellular carcinoma in vitro.