The Preparation And Modification Of Graphene Oxide And The Feasibility Study Of Loading Drugs

Graphene has been discovered in recent years, which is a new kind of carbon based single atomic layer two-dimensional crystal material with unique structure and properties. Modification of graphene has attracted a lot of attentions in many fields. In biomedical field, modified grapheme has been widely used as drug carrier. Intensive study of the modification of graphene and the mechanism of drug delivery, release mechanism, metabolic pathway, cell and molecular mechanism is still a challenging task. Based on this state, this article deeply studied the preparation and modification of graphene oxide(GO) and its feasibility as drug carrier. The main contents are as follows:1. Traditional Hummers method was improve for the preparation of GO. The natural flake graphite powder is expanded at 1000 ℃and pre-oxidized, graphene oxide with content of 57.59% oxygen is obtained. The chemical composition, morphology and structure is characterized by FTIR, AFM, Raman spectroscopy and XRD. The results show that the thickness of graphene oxide is about 1 nm, indicating its single-layer structure. The size spans from a few hundred nanometers to a few micrometres and there is superposition between the layers.2. The GO aqueous solution is ultrasonicated by cell broken instrument. The GO dispersion is obtained with uniform particle size. Through repeated experiments, the particle size in dispersion can be controlled raging from 100 to 500 nm.The GO is functional modified by grafting PEG or amino PEG. The solubility and stability of modified GO in PBS and MEMα can be significantly improved. In addition, the cytotoxicy of GO-PEG is tested by in-vitro incubation of MC3T3. The result shows when the concentration is 5ug/ml, the cell growth rate is 93.2% with 7 days culture, indicating no obvious cytotoxicity.3. Grafting FA onto GO by means of amide reaction, which was proved by means of FTIR and UV spectrophotometry. The cytotoxicity of different concentrations of GO-FA of MCF-7 is studied. After incubation of 52 h, most cells grow well. When the concentration is 5ug/ml, the cell survival rate is 85.7%. With the extension of time, GO-FA shows high affinity on cell. This indicates the complex carrier is not only low cytotoxicity, but also has a certain biological targeting effect.