Synthesis and characterization of PEGylated graphene oxide for sorafenib modified release

Graphene, a single layer of sp2-hybridized carbon atoms arranged in a honeycomb two-dimensional (2-D) crystal lattice, has evoked enormous interest throughout the scientific community since its first appearance in 2004. Due to its unique structure and geometry, graphene possesses remarkable physical-chemical properties (including large specific surface area and biocompatibility) that enable it to be an ideal material for several applications, ranging from quantum physics, nanoelectronics, energy research, catalysis and engineering of nanocomposites and biomaterials. In the area of nanomedicine, graphene and its derivatives can be exploited for a broad range of applications, including a new generation of biosensors, nanocarriers for drug delivery and probes for cell and biological imaging. In particular, graphene oxide (GO), synthesized by intensive oxidation of crystalline graphite and then turned into a monolayer material by sonication, consists of aromatic planes and polar functional groups which consequently provide it an excellent capability to adsorb aromatic compounds via π-π stacking and hydrogen bonding. In order to improve its biocompatibility and physiological stability, some biocompatible polymer can be introduced onto GO. Among the commercially available polymers, poly(ethylene glycol) (PEG) is a very useful reagent in biology because of its minimal toxicity, biocompatibility, protein resistance, and good solubility in water or other common solvents