Functionalized nanoscale graphene oxide for high efficient drug delivery of cisplatin

Graphene oxide has attracted particular interests in drug delivery. The sp(2)-aromatic structure and abundant oxygen-containing groups of nanoscale graphene oxide (NGO) were frequently utilized to load anti-cancer drugs, resulting in high loading efficiency. This research employed a polyethylene glycol (PEG, PL-PEG(2000)-NH2) functionalized NGO as a drug delivery vehicle for cis-diamminedichloroplatinum (II) (cisplatin, CDDP). The covalent reaction between platinum(II) atom and carboxylic group was utilized to attach CDDP onto NGO-PEG. The NGO, NGO-PEG, and NGO-PEG/CDDP nanohybrids were characterized by atomic force microscope imaging, transmission electron microscope imaging, Fourier transform infrared spectroscopy, and Raman spectroscopy. From the AFM images, the average thickness of the nanohybrids was ranged from 3.4 to 7.0 nm and the average sheet diameter was ranged from 21.7 to 30.5 nm. NGO-PEG demonstrated improved CDDP loading efficiency as high as 0.58 mg mg(-1). The NGO-PEG/CDDP nanohybrids released CDDP in a sustained profile for 72 h and demonstrated remarkable cytotoxicity to human breast cancer MCF-7 cells and oral adenosquamous carcinoma CAL-27 cells by in vitro assays. The drug vehicle NGO-PEG was observed nontoxic. The inhibited cell proliferation and morphology deformation induced by NGO-PEG/CDDP were further illustrated by fluorescent images.