Fabrication of biologically active surface-modified Taxolnanowires using anodic aluminum oxide templates

Abstract

Nanowires composed of the anti-cancer drug Paclitaxel (Taxol) were fabricated using solvent annealing method inside Anodic Aluminum Oxide (AAO) templates. Surface modification of the AAO template with n-octadecyltrichlorsilane (OTS), prior to loading with Taxol, prevented the nanowires from agglomerating after dissolving the template in 20% phosphoric acid. Incorporating 0.4% sodium dodecyl sulfate (SDS) with the phosphoric acid solution helped disperse the nanowires. Using this method we were able to fabricate nanowires with tunable diameters (200, 80, 55, 35 and 18 nm). Nanowires with a diameter < 80 nm formed a clear dispersion in a phosphate buffer saline (PBS) solution. These nanowires were characterized using optical and electron microscopy. The amount of Taxol in the nanowires was confirmed gravimetrically and spectroscopically using UV-Vis. Nanowires with different diameters were incubated with human monocytic U937 cells and these cells undergo morphology changes consistent with Taxol exposure. Templated nanowire growth can provide a novel strategy for the preparation of biologically active nanostructures composed of low solubility drug molecules.