Lamprey molecules squirm into the brain to deliver cancer drugs

With a mouth like a whirlpool full of teeth, the lamprey is not something you'd normally want anywhere near your brain. But now, researchers from the Universities of Texas and Wisconsin-Madison have used molecules taken from the freaky fish's immune system to deliver drugs inside the body – and even managed to sneak them into the brain.

The immune system as we know it is unique to mammals, but other kinds of animals use similar systems to protect themselves from infection. Instead of producing antibodies like humans, lampreys use small defensive molecules, and now it turns out that these might be useful for human therapies too.

But there's one place that even these lamprey molecules can't get into – the brain. Previous studies have tried to pry open the blood-brain barrier with ultrasound pulses or bee venom peptides, but the new study suggests a much simpler method. Brain tumors and Alzheimer's have been found to make that barrier "leaky," which could not only allow the drug-laden molecules to pass through, but concentrate them in the spot that needs treatment.

"Molecules like this normally couldn't ferry cargo into the brain, but anywhere there's a blood-brain barrier disruption, they can deliver drugs right to the site of pathology," says Eric Shusta, an author of the study.

To test the idea, the researchers loaded the lamprey molecules with an FDA-approved chemotherapy drug called doxorubicin. These were then administered to mice with glioblastoma, a dangerous form of brain cancer, and sure enough, the treatment significantly extended the lifespan of mice, compared to a control group.