ABSTRACT
To treat serious diseases of the central nervous system (CNS) such as Parkinson’s, meningitis, and Alzheimer’s, it is necessary for the drug to cross the endothelial membrane, in the form of the blood-brain barrier (BBB), separating the systemic circulation from the brain extracellular uid (BECF). However, owing to the impervious nature of the BBB, which comprises endothelial cells joined by tight junctions, only small and sufciently lipophilic drugs can cross this barrier, resulting in hydrophilic drugs and large molecular weight drugs, such as peptides, proteins, and antibodies, only reaching negligible levels in the CNS after parenteral application. Hence, it has not been possible to fully exploit many of these therapeutic agents for the treatment of CNS-related diseases.
