title: Covalent functionalization of graphene oxide with biocompatible poly(ethylene glycol) for delivery of paclitaxel.
abstract: Graphene oxide (GO), a novel 2D nanomaterial prepared by the oxidation of natural graphite, has been paid much attention in the area of drug delivery due to good biocompatibility and low toxicity. In the present work, 6-armed poly(ethylene glycol) was covalently introduced into the surface of GO sheets via a facile amidation process under mild conditions, making the modified GO, GO-PEG (PEG: 65 wt %, size: 50-200 nm), stable and biocompatible in physiological solution. This nanosized GO-PEG was found to be nontoxic to human lung cancer A549 and human breast cancer MCF-7 cells via cell viability assay. Furthermore, paclitaxel (PTX), a widely used cancer chemotherapy drug, was conjugated onto GO-PEG via π-π stacking and hydrophobic interactions to afford a nanocomplex of GO-PEG/PTX with a relatively high loading capacity for PTX (11.2 wt %). This complex could quickly enter into A549 and MCF-7 cells evidenced by inverted fluorescence microscopy using Fluorescein isothiocyanate as a probe, and it also showed remarkably high cytotoxicity to A549 and MCF-7 cells in a broad range of concentration of PTX and time compared to free PTX. This kind of nanoscale drug delivery system on the basis of PEGylated GO may find potential application in biomedicine.
authors.affiliation: Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, People's Republic of China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Xu
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Li
authors.forename: Mingwei
authors.initials: M
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Shi
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Huang
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D016503:Drug Delivery Systems; D004705:Endocytosis; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006108:Graphite / Q000737:chemistry* / Q000633:toxicity; D006801:Humans; D018625:Microscopy, Atomic Force; D008857:Microscopy, Interference; D010087:Oxides / Q000737:chemistry* / Q000633:toxicity; D017239:Paclitaxel / Q000737:chemistry / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000633:toxicity; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D001672:Biocompatible Materials; D010087:Oxides; D011092:Polyethylene Glycols; D006108:Graphite; D016650:Fluorescein-5-isothiocyanate; D017239:Paclitaxel
keywords: A549; MCF-7; PEG; graphene oxide; paclitaxel