Soluble, magnetically guided microrobots navigate the thinnest blood vessels to bring medicines where they are needed: clinical trials in the future.
A microrobot the size of a pink peppercorn could one day swim painlessly through the tiniest blood vessels in our brains to deliver a life-saving drug to exactly where it’s needed — for example, where a clot has formed and is blocking the flow of blood. Scientists from ETH Zurich, the Federal Institute of Technology in Zurich, are working on it, having perfected the microrobot at different levels and who describe the most recent progress on Science.
Microrobots for targeted therapies
The platform described includes a soluble microcapsule loaded with drugs, a catheter for delivering the microrobot, and a magnetic guidance system to help it move in blood vessels. The objective of the researchers led by Fabian Landers, an expert in microrobotics and minimally invasive surgery, is to ensure that the drugs can only reach the site where they are needed and that they do not have to be taken systemically, with the risk of serious side effects (such as bleeding, for anticoagulant drugs).
A traceable journey through the human body
The microrobot itself is gelatin-based and contains magnetic iron oxide nanoparticles that allow its movement to be guided remotely, as well as the drug it must deliver and radiopaque agents (i.e. which are not passed through by X-rays and which appear white on x-rays). All this allows you to guide the microrobot towards the target site while following it on the X-ray.
Scientists have navigated it through the blood vessels of anatomical brain models in humans and animals, demonstrating that it can make its way even through the thin, intricate spaces of the vascular system or through the cerebrospinal spaces.
Delivery done!
In more than 95% of cases, the microrobot, released into the blood or cerebrospinal fluid from a flexible catheter, was able to deliver the medicine exactly to the desired location. Once on site, scientists heated the nanoparticles by applying a high-frequency magnetic field, causing the capsule to dissolve and release the drug.
In addition to treating thrombosis, these microrobots could be used to treat localized infections or tumors. The next step will be to begin clinical trials on humans, although much remains to be done before seeing this technology applied in a clinical setting.
