Stem cell microbots travel from nose to brain to treat disease
Researchers in Korea have developed microbots made of stem cells that can be delivered through the nose into the brain. These “Cellbots,” which bypass the blood-brain barrier, could one day be used to treat brain cancers and neurodegenerative diseases.
As the control center of the body, the brain needs far tighter security than other organs. The blood-brain barrier is a very selective membrane that prevents toxins and foreign particles circulating in the blood from entering the brain, instead only allowing specific nutrients to pass through. And while that’s an important function most of the time, it does make it tricky to treat diseases in the brain, since drugs are also barred from getting in.
Previous research has shown that the intranasal passage can be a direct route to the brain, allowing drugs to bypass this barrier. But rather than nasal sprays or gels, scientists on the new study sent a rather unique vehicle down this highway – tiny robots made of stem cells.
The researchers created microbots made mostly of human nuclear transfer stem cells (hNTSCs), with iron oxide nanoparticles inside them. Those nanoparticles allow the Cellbots to be steered using magnetic fields. Once in the brain, the Cellbots can differentiate into neurons, neural precursor cells and neurogliocytes, which could help treat a range of nervous system disorders.
The team tested the Cellbots by first guiding them through microfluidic channels, showing how they can be controlled using an external magnetic field. Next, they transplanted them into lab-grown brain organoids, to examine their function. And finally, they demonstrated the nasal delivery method in mice, showing that the Cellbots could then be guided to the target location in the brain using magnets.
The researchers say that the new method is more effective and less invasive than surgery or other techniques to get drugs into the brain. The iron oxide particles don’t interfere with the stem cells’ work, they say, and should be safe for the brain of the recipient.
“This research overcomes the limitations in the delivery of a therapeutic agent into brain tissues owing to the blood-brain barrier,” says Professor Choi Hongsoo, co-lead author of the study, "It opens new possibilities for the treatment of various intractable neurological diseases, such as Alzheimer's disease, Parkinson's disease, and brain tumors, by enabling accurate and safe targeted delivery of stem cells through the movement of a magnetically powered hNTSC-based microbot via the intranasal pathway.”
The research was published in the journal Advanced Healthcare Materials.