A biocompatible drug delivery nanovalve system on the surface of mesoporous nanoparticles

A biocompatible nanovalve attached to the surface of MCM-41 mesoporous nanoparticles is designed to release encapsulated guest molecules controllably under pH activation. This nanovalve system is comprised of alpha-cyclodextrin (alpha-CD) rings that encircle p-anisidino linkers, and can be tuned to respond under specific pH conditions through chemical modification of the linkers. One of the distinctive features of this functional nanovalve system lies in its excellent bio-stability and durability in cell culture medium solution, the binding between the alpha-CD and p-anisidino groups was not interrupted or disintegrated by the proteins in the DMEM solution without adjusting the pH value. Luminescence spectroscopy demonstrates that the on-command pH-activated system displays very good bio-stability no drug leakage at pH similar to 7.4 and excellent drug release performance not only in H(2)O but also in cell culture medium at pH similar to 5.5. (C) 2011 Elsevier Inc. All rights reserved.