Dynamic self-assembly synthesis and controlled release as drug vehicles of porous hollow silica nanoparticles

In this paper, porous hollow silica nanoparticles (HSNS) have been successfully fabricated by a novel combination of stabilizing condensation and dynamic self-assembly. In composition, porous silica nanoparticles (MSNS-1, MSNS-2) and porous silica nanocapsules (SNC) were successfully synthesized. The silica nanostructures were characterized by small-angle X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption measurements. HSNS have higher specific surface areas and large pore volumes than MSNS and SNC. The formation mechanism of the silica nanostructures was discussed. Further, encapsulation of organic molecules into HSNS and their controlled release were investigated by using Doxorubicin (DOX) as a model. HSNS show excellent drug delivery properties. DOX-loaded silica nanostructures exhibit superb drug release behavior, which is controlled by varying the pH. The current approaches will doubtlessly open many possibilities toward biological and technological applications of silica nanomaterials. (C) 2011 Elsevier Inc. All rights reserved.