Phosphorylcholine-grafted graphene oxide loaded with irinotecan for potential oncology therapy.

2-Methacryloyloxyethyl phosphorylcholine (MPC) zwitterions were modified onto self-made graphene oxide (GO) through the atom transfer radical polymerization method. The chemical structures of the products were verified using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc. It was found that the modified GO (GO-PCn) is well dispersed in water with an average hydrodynamic diameter of about 170 nm. By utilizing the 2D planar structure of this modified graphene, the irinotecan@GO-PCn composite can be loaded with about 20% of irinotecan via π-π stacking interaction and exhibit pH-sensitive drug release performance, releasing faster in the acidic environment. The in vitro cytotoxicity assessments confirmed that GO-PCn composed of phosphorylcholine moiety represented low cytotoxicity and acted as a certain effect on reducing the acute toxicity of irinotecan, which established a foundation for further studies of the system in oncology therapy.