Synthesis and characterization of mesoporous Gd(2)O(3) nanotube and its use as a drug-carrying vehicle

Abstract

Gd(2)O(3) nanotubes were constructed for the first time by assembling highly crystalline Gd(2)O(3) nanoparticles through the use of combined soft template and sol-gel methods. Amphiphilic block copolymer was used as structure-directing agent and gadolinium isopropoxide as inorganic precursor in non-aqueous solution. The amphiphilic copolymer molecules are known to undergo self-organization above a critical micelle concentration, forming micellular architecture that further provides a structurally ordered active site for the nucleation and growth of Gd monomers. The resulting self-assembly of the Gd(2)O(3) nanocrystals led to the formation of Gd(2)O(3) tubular nanostructure after pyrolytic removal of the template. Transmission electron microscopy analysis indicated a mesoporous channel array along the [1 1 0] direction of the nanotubes where the wall of nanotube is well organized by the assembly of a highly crystalline framework of Gd(2)O(3) nanocrystals. This Gd(2)O(3) nanotube exhibited weak superparamagnetic property and was found to be able to carry and elute a model molecule, i.e. ibuprofen (IBU), in a controllable manner via an external magnetic field. The mechanism of IBU release from the nanotubes with and without the use of magnetic stimulus was proposed. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.