Magnetically Navigable Microparticles Enable Targeted Drug Delivery

Abdominal aortic aneurysms (AAA) can be life-threatening if not treated and result in nearly 10,000 deaths annually. Researchers working to improve treatments for AAA could now make it possible for doctors to direct life-saving therapies through the body using only a magnet.

An interdisciplinary team at the University of Pittsburgh’s Swanson School of Engineering (Pittsburgh, PA, USA) has developed silk iron microparticles (SIMPs)—tiny, magnetic, and biodegradable carriers designed to precisely deliver drugs and treatments to targeted sites in the body, such as aneurysms or tumors. By enabling early-stage, noninvasive delivery of regenerative therapies via extracellular vesicles—membrane capsules that facilitate intercellular communication—the researchers aim to reduce the need for surgical interventions in treating AAA. The team’s goal was to find the most noninvasive method for delivering extracellular vesicles directly to the site of an AAA. They envisioned injecting extracellular vesicles onto a carrier and guiding the carrier to the aortic wall, using magnetic attraction.

The magnetic nanoparticles developed by the team are approximately one-hundred-thousandth the width of a human hair. At this minuscule scale, nanomaterials can be engineered to exhibit unique properties, such as magnetic responsiveness. While magnetically guided materials have been used in various medical applications, the team’s innovative approach involved chemically binding the magnetic nanoparticles to silk—a biocompatible material approved by the FDA—using the compound glutathione. This research, published in ACS Applied Materials & Interfaces, opens up numerous possibilities for future applications, ranging from targeted cancer therapies to regenerative treatments for cardiovascular diseases. With the ability to magnetically guide the particles, the next step is to load them with therapeutic agents. At the nanoscale, these findings also allow the team to further refine the particles’ molecular structure and control their drug release rates, enhancing their potential for biomedical use.

“With this paper, we’re showing that we can create an empty carrier that can be magnetically moved,” said Pitt alumna Ande Marini (BioE PhD ‘25), now a postdoctoral scholar in cardiothoracic surgery at Stanford University. “The next step is figuring out what kind of cargo we can load—regenerative factors, drugs, or other materials people want to magnetically localize. Whether it’s delivering cancer drugs with fewer side effects or slowing down tissue degradation in aneurysms, this technology has broad potential for regenerative medicine.”