Graphene Based Nanomaterials: Synthesis, Characterization And Bioapplications

Graphene, a rising star of two-dimensional material, has become one of thehot-spot focuses due to its unique structure, excellent physical and chemical propertiesand other characteristics. A lot of research groups have reported a great quantity of workabout surface functionalization and bioapplications of graphene and graphene oxide inrecent years. Several polymers were used for surface modification of graphene in orderto improve its solubility and biocompatibility. Some nanoparticles could also be grownonto the surface of graphene. Graphene and graphene oxide with good surfacemodification has been reported to be used for drug delivery, cytology fluorescentimaging and other bioapplications. In this work, graphene oxide (GO) is modified byhydrophilic biocompatible polymers such as dextran and polyethylene glycol, and its invitro and in vivo behaviors are tested.In Chapter One, we summarized the current progresses in field of grapheneresearch.In Chapter Two, we used dextran (DEX), a natural polymer, to modify the surfaceof GO. The in vitro cytotoxicity and cell entry mechanism of the obtained GO-DEXwere studied. We next explored the in vivo biodistribution and pharmacokinetics usingradioactive labeled GO-DEX.In Chapter Three, polyethylene glycol (PEG) coated GO was tested in vivo and invitro. Fluorescently labeled GO-PEG was used as an excellent probe of several tumormodels. Photothermal therapy of mouse tumor with this material showed excitingtherapeutic results.In Chapter Four, we explored the method of growing other inorganicnanostructures like magnetic iron oxide, silver and gold nanoparticles on the surface ofgraphene. Then some characterization methods were used to study the topography,optical and magnetic properties of these graphene based composite materials.In summary, our work revealed that functionalized graphene and its nano-composite may have great promise in biomedicine, for potential applications indrug delivery, photothermal therapy, and biomedical imaging.