Functionalization of graphene sheets for the development of gene delivery system
Graphene is considered a class of two-dimensional sp2 carbon nanomaterials which has attracted tremendous attentions for medicinal fields in the past decade, like gene and drug delivery. The using of graphene as a non-viral carrier for gene delivery considered an alternative for viral delivery, which suffered from various drawbacks and can be fatal. Utilizing its unique physical and chemical properties of graphene makes it the most studied materials these days. The aim of this work is the covalent functionalization of pristine graphene sheets with polyamine to improve the transfection and the efficacy of pDNA onto the cells where is expressed. Graphene sheets have successfully covalently functionalized with polyamine group through click reaction in the presence of tetraethyelene glycol linker to improve the solubility and dispersibility of the developed nano-graphene gene delivery. The transmission electron microscope images demonstrates good dispersability and the degree of functionalization was quantified using the thermogravimetric analysis obtaining (58%) of the functionalization. Moreover, the surface charge of the functionalized graphene was +20 mV as confirmed by zeta potential analysis. The complexion of f-graphene-pDNA exhibits ability to condense DNA at low mass ratio (10:1). The in vitro transfection of f-graphene loading enhanced green fluorescent protein gene (pEGFP) indicates effectively expression of deliver plasmid GFP gene onto HeLa cell within 1 h. Finally, the cytotoxicity profile of f-graphene evaluated by MTS assay showed excellent cell availability under controlled condition. Taken together, chemistry functionalization of pristine graphene with polyamine could possibly use for development new non-viral gene delivery.