ROCKVILLE, Md. — Diseases of the nervous system are typically treated with drugs, administered systematically. Now, a robot likened to the tiny body-exploring craft depicted in the 1960s sci-fi flick “Fantastic Voyage” has been created that delivers drugs directly to the central nervous system. Scientists say the device offers hope of new therapies for a host of illnesses ranging from cancers to Alzheimer’s, Parkinson’s, and multiple sclerosis.
Diseases that affect the central nervous system are hard to treat as drugs have to cross the blood-brain barrier. The blockade of dense cells and vessels protects grey matter against circulating foreign bodies. It is too solid for most cells/pathogens to pass through.
“Delivering drugs orally or intravenously, for example, to target cancers or neurologic diseases, may affect regions of the body and nervous system unrelated to the disease. Therefore, targeted drug delivery may lead to improved efficacy and reduced side-effects due to lower off-target dosing,” explains project leader Dr. Lamar Mair of medical device company Weinberg Medical Physics, in a statement.
The device, named MANiAC, which stands for magnetically aligned nanorods in alginate capsule, is powered wirelessly by electromagnetic waves since magnetic fields are not influenced by tissues, and tend to be very safe. In the Raquel Welch film “Fantastic Voyage,” a team of scientists was shrunk inside a submarine and injected into a dying patient. They traveled through veins into his brain and destroyed a blood clot with laser guns.
It is hoped MANiAC will soon be doing a similar job, unleashing payloads that combat strokes, tumors, or other life-threatening conditions. “It may be part of an advanced arsenal of drug delivery technologies at doctors’ disposal,” says Dr. Mair. The team tested the robot under conditions it may experience, such as the undulating and tortuous architecture of the nervous system.
The study is the first to demonstrate how a micro-robot might perform in the central nervous system, including the brain.
MANiAC contains magnetic nanorods encased in a soft spherical shell and is controlled using a magnetic field. In experiments, the tiny tumbling soft robot moved against fluid flow, climbed slopes, and moved about the spinal cord and other neural tissues. It was capable of precisely discharging substances at precise locations.
The terrain included flowing cerebral spinal fluid and slopes, to which the MANiACs were able to climb slopes with increasing steepness, and move against flowing liquid. They also moved along rat brain and mouse spinal cord tissues and deposited dye on their surfaces – a substitute for drugs. The technique enables them to “tumble” through the body, drawing them to a target site for drug delivery.
Under magnetic stimulation, the MANiACs successfully scaled slopes as steep as 45 degrees. They went upstream against a fluid similar to what they would encounter in the nervous system. The researchers maneuvered dye-loaded MANiACs around on the surface of rodent neural tissues with a fine degree of control. The dye was left in exactly the right spots. They even re-dosed several places to increase the amount of “drug” to that area.
“The ability to go back and re-dose regions which received insufficient dose upon initial treatment is significant. These results are very preliminary and highly experimental, but we think we have demonstrated strong evidence that small, soft, capsule-based microrobots have the potential for controlled local delivery in neural diseases,” notes co-author David Cappelleri, a professor at Purdue University.
MANiAC is described in the journal Frontiers in Robotics and AI.
South West News Service writer Mark Waghorn contributed to this report.