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Is It Possible to Treat Some Brain Diseases by Drug-Substituted Zeolites?

To the Editor: The blood–brain barrier (BBB) contains microvascular endothelial cells (ECs) linked by tight junctions. ECs restrict the diffusion of large molecules into the cerebrospinal fluid (CSF), while allowing the diffusion of small, hydrophobic molecules. The size of materials that can cross the BBB is in the range of 30 nm–280 nm.1

Nanomaterials have a functional organization in one or more dimensions, usually less than 100 nm. A kind of inorganic, highly porous nanomaterial called zeolite, contains crystals that have a network of nanopores. The size of these crystals may range from micrometer to nanometer, based on applied synthesis parameters such as pH, kind of Ingredients, temperature, and crystallization time.2

On the other hand, zeolites are used in many in-vitro and in-vivo applications. Research has demonstrated the use of metal exchanged zeolites as an alternative storage and delivery device for nitric oxide in human physiology.3 In another work, the Zn2+ -exchanged clinoptilolite-rich rock is used as an active carrier for antibiotics in anti-acne topical therapy.4 In addition, zeolites are used to recovery of nitrogen and phosphorus from urine.5

We hypothesize that if a zeolite-containing drug solution is prepared and injected into the blood, these drug-substituted zeolites may cross the BBB to treat some brain diseases. Two examples of such benefits are using zeolites to carry some peptides into the central nervous system in order to improve cognition, and transporting antibodies with very high affinity for β−amyloid protein in order to manage Alzheimer’s disease. Surely, clinical data must be collected to uphold the safety of this hypothesis.

Biomedical Engineering Faculty, Amirkabir University of Technology
References

1 Huh AJ, Kwon YJ: “Nanoantibiotics:” a new paradigm for treating infectious diseases using nanomaterials in the antibiotics resistant era. J Control Release 2011; 156:128–145Crossref, MedlineGoogle Scholar

2 Ding L, Zheng Y: Nanocrystalline zeolite beta: the effect of template agent on crystal size. Mater Res Bull 2007; 42:584–590CrossrefGoogle Scholar

3 Wheatleya PS, Butlerb AR, Cranec MS, et al.: Zeolites for storage and delivery of nitric oxide in human physiology. Molecular Sieves: From Basic Research to Industrial Applications. Proc of the 3rd Int. Zeolite Symposium, Prague, Czech Republic, 2005; 158:2033–2040Google Scholar

4 Bonferoni MC, Gerri G, de’ Gennaro M, et al.: Zn2+-exchanged clinoptilolite-rich rock as active carrier for antibiotics in anti-acne topical therapy in-vitro characterization and preliminary formulation studies. Appl Clay Sci 2007; 36:95–102CrossrefGoogle Scholar

5 Ganrot Z, Dave G, Nilsson E: Recovery of N and P from human urine by freezing, struvite precipitation, and adsorption to zeolite and active carbon. Bioresour Technol 2007; 98:3112–3121Crossref, MedlineGoogle Scholar