Drug Delivery Robots Send Meds Through the Body to the Heart

Engineers at Johns Hopkins University have developed micro-robots designed to travel inside the body and treat severe heart infections, specifically endocarditis.

About 50,000 people in the U.S. contract the infection annually. Traditionally, doctors treat the heart tissue infection with weeks of IV antibiotics. A major issue, however, is that those drugs often get diluted before reaching the heart. As a result, doctors must choose between toxic antibiotic doses or risky open-heart surgery.

Delivery Straight to the Heart

This is where the new robots come in handy. Researchers say they’re as wide as a pencil tip, and as long as a grain of rice.

These micro-robots work in pairs. First, a needle module latches onto the infected heart tissue, acting as a docking station. Then, a drug module delivers medicine directly to that spot, docks magnetically, and slowly releases the antibiotic.

External electromagnetic coils guide both magnetic bots from outside the body, similar to how an MRI operates.

“Magnetic guidance is exciting because you don’t have to power the robot itself. It doesn’t carry batteries and motors,” said senior author Axel Krieger. “The drugs can be delivered safely, with technology like the gradients and fields in an MRI. But instead of using it for imaging, it drives the millirobots.”

Faster Treatments and Broader Uses

The team published their work in Advanced Material Technologies. They tested the robots on heart models and real porcine heart tissue, in which the devices moved smoothly under simulated blood flow.

“We can just inject a robot with a little pill into your vein where it travels to the site, right to where we really need to deliver the drugs, and it’s minimally invasive,” said first author Anuruddha Bhattacharjee.

“Usually if you do IV drug treatment, you need four to six weeks of therapy. But with these robots, the entire procedure might take 10 minutes—maybe an hour if you want to do a couple rounds,” Bhattacharjee added. “If everything works well, you go from four to six weeks of treatment to one day or less.”

Beyond heart infections, the team notes that the steerable robots could also help treat other hard-to-reach conditions, such as cancer.