Amphiphilic TiO2 nanotube arrays: an actively controllable drug delivery system.

Amphiphilic TiO(2) nanotube arrays are fabricated by a two-step anodization procedure combined with hydrophobic monolayer modification after the first step. These tubes can be used as biomolecular carriers, where the outer hydrophobic barrier provides an efficient cap against drug leaching to the environment. By utilizing the photocatalytic ability of TiO(2), a precisely controlled removal of the cap and a highly controlled release of the hydrophilic payload (drug) can be achieved.