New Delivery System For Brain Targeting

Effective delivery of drugs to treat specific diseases of the central nervous system remains a problem because of poor transport through the capillary endothelial wall that makes up the blood-brain barrier. A potentially widely-applicable means of circumventing this problem has now been described in the Proceedings of the National Academy of Sciences (March 27).

The researchers used the protein transferrin as the basis for the transport system, because receptors for this molecule are plentiful in the blood-brain barrier. They fused antibody fragments to transferrin that could be used to deliver agents or seek a secondary target once in the brain. The researchers injected the transferrin-antibody fusion proteins into the tail veins of rats, and found that up to 0.3% of the dose passed the barrier intact and able to bind antigen. While the work is still at an early stage, it indicates that the approach may in principle be effective.