The blood-brain barrier, while being a bulwark for the brain, protecting it from danger, can also be a nemesis for some. Delivering foreign compounds across this barrier for imaging or therapy has been formidable for years. Earlier approaches were akin to using a sledgehammer where a screw driver was warranted, usually weakening the barrier using harsh chemical intervention.

Evaluation of magnetic carriers

This method involves the administration of an imaging dye encapsulated inside biodegradable polymeric nanoparticles with an iron oxide core. These particles distribute throughout the circulatory system, and under the influence of a weak magnetic field applied to the head, accumulate near the brain. As a result, researchers observe a much higher brain concentration of the encapsulated dye compared with control experiments.

These nanoparticles are completely biodegradable. The iron oxide cores are absorbed into the hemoglobin cycle and thus pose no danger. The polymeric matrices are also harmlessly metabolized.

Breaking through the roadblock

Delivering drugs to brain tissue is still tough, but scientists are constantly making headway towards that elusive goal. Imaging select regions in the brain has been troublesome, requiring invasive methods. This method significantly reduces the amount of therapeutic/imaging agent to be administered in order to produce a biologically relevant concentration in the brain.

Our future goals would be to further reduce the intensity of the external magnetic field as well as control the exact site of delivery within the brain.

The researchers presented their work in the journal Nanotechnology.