New approaches to drug delivery through the blood-brain barrier.

The development of recombinant proteins, monoclonal antibodies, or antisense oligonucleotides as pharmaceuticals for the brain will require the parallel development of practical strategies for delivery of these pharmaceuticals in vivo through the endothelial wall of capillaries in the brain, the blood-brain barrier. The brain and spinal cord constitute the only organ to be perfused by capillaries having such a barrier, which excludes the uptake into the brain of circulating molecules that do not have access to several specialized transport systems within the barrier. The current challenge for biotechnology is to develop effective drug-delivery strategies to the brain in parallel with the ongoing drug-discovery programs for this organ.