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.