Various groups are currently working on tiny “robots” that could deliver medication to specific locations within the body. One of the latest such microbots, known as the MANiAC, is designed specifically for use in the delicate and challenging central nervous system.
Its name an acronym for “magnetically aligned nanorods in alginate capsules,” the MANiAC is currently being developed by a consortium of US research institutes and biotechnology companies.
As is the case with other drug-delivery microbots, the idea is that it will be loaded with a pharmaceutical payload, guided through the patient’s body to the place where the medication is needed, then allowed to release its payload. As compared to traditional approaches – in which drugs affect the whole body after being taken orally or injected into the bloodstream – less medication will be required, and side effects will be minimized.
Each “millimeter-scale” MANiAC consists of a cluster of aligned magnetic nickel nanorods, encased within a soft spherical alginate shell. When subjected to a rotating magnetic field – which could be generated by an electromagnet located outside the patient’s body – the microbot tumbles/rolls in the direction of the rotation. Therefore, by slowly moving the electromagnet, it’s possible to guide the MANiAC from one place to another.
In lab tests, the microbots were able to climb slopes as steep as 45 degrees, and move upstream against a fluid flow similar to what they would experience in the central nervous system. They were also able to move across rat brain tissue and then pause in specific locations on that tissue, releasing green dye that represented a medicinal payload.
The scientists now hope that it may someday be possible to inject MANiACs into the spinal cord and then guide them up through the cerebral spinal fluid and into the brain, bypassing the blood/brain barrier.
“These results are very preliminary and highly experimental, but we think we have demonstrated strong evidence that small, soft, capsule-based microrobots have potential for controlled local delivery in neural diseases,” says team member Prof. David Cappelleri, of Indiana’s Purdue University.
The research is described in a paper that was recently published in the journal Frontiers in Robotics and AI.