A dysfunctional blood–brain barrier and cerebral small vessel disease

In molecular terms, the blood–brain barrier (BBB) indicates tight junction complexes between adjacent endothelial cells that, combined with endothelial transporters (both influx and efflux), make brain endothelia different from other endothelia. While highly advantageous as a protective barrier against cerebrovascular permeability, shielding sensitive brain elements from blood-borne agents, it also poses a problem for those who seek to develop brain therapeutics such as designer antibodies targeted to amyloid deposits or tau protein derivatives.