Study On The Non-covalent Functionalization And Drug Loading System Of Graphene

In this paper, we sutdied the non-covalent functionalization of graphene and theapplication of modified graphene on delivery of hydrophobic drugs as nano-drugcarriers. Meanwhile, we invented a novel new green approach to reduce grapheneoxide to graphene.The Pluronic PF127modified graphene nanosheet (PF127/GN) hybrid wasprepared via an one-pot process including the simultaneous reduction of grapheneoxide and assembly of PF127and GN. The nanohybrid exhibits highwater-dispersibility and stability in physiological environment with the hydrophilicchains of PF127extending to the solution while the hydrophobic segmentsanchoring at the surface of graphene via hydrophobic interaction. The PF127/GNnanohybrid is found to be capable of effectively encapsulating doxorubicin (DOX)with ultrahigh drug loading efficiency (289%w/w) and exhibits a pH responsivedrug release behavior. The superb drug loading efficiency of the PF127/GNnanohybrid relies on the introduction of GN which is structurally compatible withDOX. Cellular toxicity assays performed on human breast cancer MCF-7cellsdemonstrate that the PF127/GN nanohybrid displays no obvious cytotoxicity, whilethe PF127/GN loaded DOX (PF127/GN/DOX) shows remarkable cytotoxicity to theMCF-7. Cell internalization study reveals that PF127/GN nanohybrid facilitates thetransfer of DOX into MCF-7cells, evidenced by the image of confocal laserscanning microscopy. The above results indicate the potential application of thisnovel nanocarrier in biomedicine. A simple and environmental friendly reductive route to prepare soluble graphenefrom exfoliated graphene oxide employing β-cyclodextrin as both reducing agent andstabilizer was reported. The as-prepared graphene was characterized by FT-IR,UV-Vis, XRD, Raman spectroscopy, XPS and the results confirmed the successfulreduction of graphene oxide. Furthermore, we explored the possibility of preparedgraphene in biomedical application and drug loading. It was found that the grapheneobtained exhibited high dispersion in various physiological solution including water,PBS, serum and cell medium. Using carboxyfluorescein as model drug, we alsoexplored the loading efficiency of the graphene nanosheet, and it was found that theloading efficiency can reach as high as110%with a drug concentration of0.45mg/mL.