Single-Walled Carbon Nanotubes Functionalization for the Delivery of the Water Insoluble Anticancer Agent Indole-3-Carbinol Cyclic

Single-walled carbon nanotubes (SWNTs), despite their low solubility in aqueous solutions that limits their use in biological applications, have been proposed as delivery systems for a variety of therapeutic agents due to their unique structural and physicochemical properties. Previously we have shown that SWNTs solubility, biocompatibility, and cell penetration could be improved coating carbon scaffolds with aliphatic carbon chains and, eventually, phospholipids to obtain micellelike structures. In this paper we show that oxidized SWNTs covalently coupled with an alcoholic chain (stearyl alcohol, C18H37OH) could promote the solubility and antiproliferative activity of 5,6,11,12,17,18,23,24-octahydrocyclododeca[1,2-b:4,5-b′:7,8-b′′:10,11-b′′′]tetraindole (CTet), an indole-3-carbinol (I3C) metabolite endowed with anticancer properties. SWNTs and their derivatives used in these studies have not antiproliferative and cytopathic effect on two breast cancer cell lines investigated. In contrast, CTet formulated with C-18 SWNT-derivative (SWNTs-COOC18H37) was able to induce cell death and inhibition of cell proliferation in both MCF-7 and MBA-MB-231 human breast cancer cell lines. Thus, derivatized SWNTs-COOC18H37 are able to deliver CTet to breast cancer cell lines in an efficient way.