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Journal of Nanomaterials
Volume 2014 (2014), Article ID 507178, 8 pages
Research Article

Preparation and Characterization of Kynurenic Acid Occluded in Sol-Gel Silica and SBA-15 Silica as Release Reservoirs

1Nanotechnology Laboratory, National Institute of Neurology and Neurosurgery, 14269 Mexico City, Mexico
2Department of Chemical and Molecular Engineering, Tulane University, New Orleans, LA 70118, USA
3Nanotechnology and Nanomedicine Laboratory, Autonomous Metropolitan University-Xochimilco, 04960 Mexico City, Mexico
4Institute of Physics, National Autonomous University of Mexico, 01000 Mexico City, Mexico
5Neurochemistry Department, National Institute of Neurology and Neurosurgery, 14269 Mexico City, Mexico
6Neuroscience Department, Subdivision of Neurobiology, National Institute of Rehabilitation, 14389 Mexico City, Mexico
7El Colegio Nacional, 06020 Mexico City, Mexico

Received 4 March 2014; Revised 9 May 2014; Accepted 9 May 2014; Published 29 May 2014

Academic Editor: Abdelwahab Omri

Copyright © 2014 Tessy López et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Kynurenic acid (KYNA) may have important therapeutic effects in neurological disorders; however, its use as a neuroprotective agent is restricted due to its very limited ability to cross the blood brain barrier (BBB). For this reason, we are looking for new alternatives for KYNA to reach the brain; one of them is using drug delivery systems. To obtain KYNA release reservoirs, KYNA molecules were hosted in two different silica materials. The different KYNA-silica materials were characterized by means of several physical techniques. The spectroscopic studies showed that KYNA molecules remained unchanged once hosted in silica materials. The surface area values of KYNA-silica samples were substantially lower than those for pure silica materials due to the addition of the drug. The electronic micrographs showed that the sol-gel KYNA-silica material consisted of aggregates of nanoparticles around 50 nm in size. On the other hand, the typical SBA-15 hexagonal arrangement was observed, even when hosting KYNA molecules. KYNA release profiles, carried out during approximately 300 hours, showed a first stage of fast drug release followed by a slow release phase. The experimental values fitted to the Peppas equation indicate that the release mechanism was controlled by Fickian diffusion.