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

Abstract

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.

Evaluation of solubility enhancement, antioxidant activity, and cytotoxicity studies of kynurenic acid loaded cyclodextrin nanosponge

“…Hornok and co-workers prepared KYNA loaded micelles to demonstrate the pharmacological activity of KYNA on systemic administration (Hornok et al, 2012). Moreover, López et al earlier demonstrated the synthesis of KYNA loaded silica nanoparticles to improve the solubilization of KYNA (López, Ortiz, Gómez, la Cruz, Verónica Pérez-de Carrillo-Mora, & Novaro, 2014). Different ester derivatives of KYNA were also prepared to improve its solubility and permeability (Dalpiaz et al, 2005).…”

Preparation and characterisation of silica‐based nanoparticles for cisplatin release on cancer brain cells

“…Simulated cerebrospinal fluid (SCF) was used as a release medium, and it was prepared according to information reported by Düzlü et al [34]. The release profiles were made based on the methodology reported by Lopez et al [31] Approximately 10 mg of each CP-MSNPs or CP-SiNPs sample was slightly pressed to form a small cylinder which was added to 25 mL of SCF (pH = 7.3) maintaining the release medium with moderate stirring (50 rpm) at 25°C. At predetermined times an aliquot of 3 mL was removed from the release medium for its measurement by UV spectroscopy.…”

“…Currently, new drug delivery systems based on MSNPs have been developed and are being used as release systems for a considerable variety of drugs such as antibiotics, anti-inflammatory compounds, chemotherapy, and neurological disorders medications [28][29][30][31].…”

Tautomeric polymorphism of the neuroactive inhibitor kynurenic acid

“…The protective effect of KYN, as well as the discovery and development of new prodrugs for an effective treatment of CNS disorders, are quite well investigated in terms of biology and medicine Walczak et al, 2014). KYN is incorporated into nanocarriers for drug encapsulation and delivery systems (Modi et al, 2009;Kabanov & Gendelman, 2007;Ló pez et al, 2014). Recently, KYN has been studied also with respect to its antitumour activity.…”