Researchers have developed 'nanoswimmers' that cross the blood brain barrier highly efficiently. The 'nanoswimmers' are made from mixtures of fat molecules strung together (lipid polymers.) Similar to the outside of a cell, the polymers attract water at one end and repel water at the other.
The blood brain barrier is notoriously difficult to penetrate. Though this keeps microbes, toxins and large molecules out of the brain, it also prevents potentially lifesaving medicines from reaching the brain.
To tackle this problem researchers filled the polymers with a substance that breaks down glucose. Because of this substance the polymers are extremely attracted to glucose, the higher the levels of glucose the more they will move toward this area, this is called chemotaxis. Neurons use this same form of movement to move through the developing brain.
Researchers made the polymers lopsided. One side digests the glucose and the other side releases the waste product from the digestion process. This release of waste propels the polymer towards more glucose, like a rocket.
Due to the high concentrations of glucose in the brain the polymers are naturally drawn towards it. This combined with the protein LRP1, a protein abundant in the cells in the blood brain barrier, makes these specific polymers four times more efficient in moving through the blood brain barrier than other combinations of polymers tested.
Teams are now working toward using this technology to target brain tumours and deliver cancer-killing drugs directly to them.