Synthesis of TiO 2 nanostructured reservoir with temozolomide: Structural evolution of the occluded drug T. Lo ´pez a , J. Sotelo b , J. Navarrete c , J.A. Ascencio c, * a Depto. Quı ´mica, Universidad Auto ´ noma Metropolitana-Iztapalapa, Mexico b Instituto Nacional de Neurologı ´a y Neurocirugı ´a ‘‘Manuel Velasco Sua ´ rez’’, Me ´xico, DF, Mexico c Instituto Mexicano del Petro ´ leo, La ´ zaro Ca ´ rdenas 152, San Bartolo Atepehuacan, Me ´xico, DF 07730, Mexico Available online 5 June 2006 Abstract Sol–gel synthesized nanostructured TiO 2 matrix were produced with different channel sizes, where drug are immersed, producing a reservoir with Temozolomide (TMZ). This drug is particularly important for the treatment of cancer tumors, which are fundamentally a consequence of the uncontrolled reproduction of human cell. In this way the chemotherapy plays an important role in the treatment of both recurrent and newly diagnosed patients. In the handling of brain tumors TMZ has been discovered as a recent and efficient second generation drug employed in the control of advanced brain gliomas, and it is a welcome addition. Its active component binds to the cancerous DNA cells, thus preventing their disordered growth, destroying them. In this work, we report the synthesis of TiO 2 nanostruc- tured reservoir with TMZ, focusing the effort to the understanding of structural effects on the TMZ configuration by using nuclear mag- netic resonance, Raman and IR spectroscopy methods. Our results establish that TMZ molecules are quite sensible to chemical processes and it produces the activation of the molecule, which is followed and understood with help of quantum molecular simulation methods. The study of the molecules allows determining the conditions that produce the activation and chemical selectivity of the molecules, which determines the conditions of synthesis. This information gives parameters for the reservoir structural and chemical optimization. Ó 2006 Elsevier B.V. All rights reserved. 1. Introduction One of the main goals for all the new nanostructured materials is to find optimal conditions of synthesis for being applied in a particular function [1]. In this way the synthesis parameters are related directly to the expected properties, and consequently the materials design depends on the understanding of the involved behavior of the mate- rial. This becomes particularly important for the possible use of nanostructured reservoirs in drug delivery processes, the understanding of the produced structures and the cor- responding effects on the drug molecules, which are consid- ered to administrate [2,3]. In previous reports we have demonstrated the synthesis of nanostructured reservoirs based on TiO 2 [2] and SiO 2 [3] aggregates producing por- ous matrixes, which are obtained by sol–gel methods. These structures have demonstrated to generate morpholo- gies with channels [2] and tubular shapes [3], while the own drug molecules act as micelles keeping the internal struc- ture of the channels. The use of nanostructured reservoirs for drug delivery has been focused mainly to the treatment of neurodegener- ative diseases as epilepsy or cancer tumors. In this way, cancer is a disorder of the processes of cellular growth, development, and repair. It consists fundamentally in an uncontrolled growth of cells that differ morphologically and biochemically from the original ones. Tumors of the central nervous system (CNS) are the most frequently found in children (70–80%), and they arise from glial cells tending to metastasize outside the CNS unless there is a surgical intervention. Chemotherapy plays an important role in the treatment of both recurrent and newly diag- nosed patients. One of the most important recent means to control and treat these CNS tumors is provided by the 0925-3467/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.optmat.2006.03.033 * Corresponding author. Tel.: +52 55 91758461; fax: +52 55 91756429. E-mail addresses: tesy@xanum.uam.mx (T. Lo ´ pez), ascencio@imp.mx (J.A. Ascencio). www.elsevier.com/locate/optmat Optical Materials 29 (2006) 88–94