Combined Adsorption and Covalent Linking of Paclitaxel on Functionalized Nano-Graphene Oxide for Inhibiting Cancer Cells

[Image: see text] Developing targeted delivery nanosystems for delivering chemotherapeutic anticancer drugs specifically to cancerous tissues with improvement in the specificity of drugs for different cancer cells can result in high therapeutic efficacy and low toxicity in healthy tissues. Herein, we proposed the synthesis of a multifunctional nanodelivery system, folic acid (FA) decorating nanographene oxide (nGO) functionalized with poly(ethylene glycol) (PEG), called pGO-FA, with good biocompatibility and good delivering performance of a hydrophobic water-insoluble anticancer drug of paclitaxel (PTX). 4-br-PEG-NH(2), FA, and PTX were attached to PEG-functionalized nGO (pGO) through a combined chemical and physical force to form a nanosized complex, pGO-FA-PTX, defined as the nanodrug system. WST-8 assay in vitro illustrated that pGO-FA-PTX inhibited A2780 cells in a concentration-dependent manner. Cell viability was kept high to 60% when treated with 200 nM of free PTX. However, pGO-FA-PTX with the same dose of PTX (cell viability less than 30%) had double the cytotoxicity effect compared to free PTX. Furthermore, fluorescence observation demonstrated that pGO-FA-PTX exhibited an improved efficiency in killing A2780 cells due to the special affinity between FA and FA receptor, which has high expression in cancer cells. The strategy and method used in this study could be effective in improving both the bioavailability of PTX and therapy efficiency.