Characteristics of compounds that cross the blood-brain barrier

Substances cross the blood-brain barrier (BBB) by a variety of mechanisms. These include transmembrane diffusion, saturable transporters, adsorptive endocytosis, and the extracellular pathways. Here, we focus on the chief characteristics of two mechanisms especially important in drug delivery: transmembrane diffusion and transporters. Transmembrane diffusion is non-saturable and depends, on first analysis, on the physicochemical characteristics of the substance. However, brain-to-blood efflux systems, enzymatic activity, plasma protein binding, and cerebral blood flow can greatly alter the amount of the substance crossing the BBB. Transport systems increase uptake of ligands by roughly 10-fold and are modified…

• MJ
  Michael J. Fox Foundation for Parkinson's Research
• EL
  Eli Lilly and Company
• S
  Sanofi
• B
  Biogen
• NI
  National Institutes of Health
• NI
  National Institute on Aging
• NI
  National Institute of Neurological Disorders and Stroke