Biological barrier permeability

Biological barrier permeability is a physiological property rather than a specific molecular target; it describes the capacity of cellular interfaces, such as the blood-brain barrier (BBB) or intestinal epithelium, to regulate the passage of ions and molecules (NIH, 2023). These barriers are primarily formed by endothelial or epithelial cells sealed by junctional complexes, including tight junctions and adherens junctions, which prevent the uncontrolled paracellular movement of substances (PubMed, 24715433). This selectivity is crucial for maintaining organ-specific homeostasis and shielding sensitive tissues from pathogens and toxins (StatPearls, NBK557609). Pathological changes in permeability are associated with various conditions, such as neuroinflammation in multiple sclerosis or 'leaky gut' in inflammatory bowel disease (PubMed, 18454112). In drug development, permeability is a decisive factor for drug delivery, especially for CNS-targeted therapies, where strategies may include the use of osmotic agents like mannitol to transiently increase barrier opening (PMC, 460848).

Other names

Barrier integrityMembrane permeabilityEndothelial permeabilityEpithelial permeabilityParacellular permeability

Modulation of tight junction proteins (e.g., claudins, occludins) or osmotic disruption of endothelial cell layers to facilitate or restrict solute passage.