Synthesis and characterization of PEGylated graphene oxide for sorafenib modified release

Graphene, a single layer of sp2-hybridized carbon atoms arrangedin a honeycomb two-dimensional (2-D) crystal lattice, has evoked enormousinterest throughout the scientific community since its first appearance in2004. Due to its unique structure and geometry, graphene possesses remarkablephysical-chemical properties (including large specific surface areaand 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 areaof nanomedicine, graphene and its derivatives can be exploited for a broadrange of applications, including a new generation of biosensors, nanocarriersfor drug delivery and probes for cell and biological imaging. In particular,graphene oxide (GO), synthesized by intensive oxidation of crystallinegraphite and then turned into a monolayer material by sonication, consistsof aromatic planes and polar functional groups which consequently provideit an excellent capability to adsorb aromatic compounds via π-π stacking andhydrogen bonding. In order to improve its biocompatibility and physiologicalstability, some biocompatible polymer can be introduced onto GO. Amongthe commercially available polymers, poly(ethylene glycol) (PEG) is a veryuseful reagent in biology because of its minimal toxicity, biocompatibility,protein resistance, and good solubility in water or other common solvents.