Poly(N-vinyl caprolactam) grown on nanographene oxide as an effective nanocargo for drug delivery

This study evaluated graphene oxide functionalized covalently with poly N-vinyl caprolactam (GO-PVCL) via in situ atomic transfer radical polymerization (ATRP), as a nano-cargo carrier for the efficient delivery of drugs into cells. Water-soluble GO-PVCL exhibited excellent stability in physiological solutions. An anti-cancer drug, camptothecin (CPT), was then loaded onto GO-PVCL with a high payload (20%) through pi-pi stacking and hydrophobic interactions, and its release could be controlled by varying the pH. PVCL grafted onto GO offers an additional advantage of targeted delivery according to temperature. GO-PVCL showed no obvious toxicity, whereas the CPT-loaded GO-PVCL showed high potency in killing cancer cells in vitro. The drug transportation mechanism was found to be energy-dependent endocytosis. Overall, this study revealed GO-PVCL to be a promising drug delivery vector with high biocompatibility, solubility and stability in physiological solutions, and good payload capacity owing to its small size, low cost, large specific area, ready scalability, and useful non-covalent interactions. This material is expected to be a novel material propitious for biomedical applications. (C) 2013 Elsevier B.V. All rights reserved.