Microscopic robots to treat inflammatory bowel disease

Written By Mark

Engineers from the University of California, San Diego, USA, have developed a pill that contains very small devices that represent microscopic robots that can move and work inside the human body. The pill releases these microscopic robots into the colon to treat inflammatory bowel disease.

The experimental treatment, which is given orally, has proven successful in mice, according to the journal Science Robotics, which published the results of the innovation on June 26, and was written about by the EurekAlert website.

Inflammatory bowel

Inflammatory bowel disease (IBD) is an autoimmune disorder characterized by chronic inflammation of the intestines, causing severe abdominal pain, rectal bleeding, diarrhea, and weight loss. Autoimmune diseases occur when the body’s natural defense system cannot distinguish between normal cells and foreign cells, causing the body to mistakenly attack normal cells.

Inflammation of the intestine occurs when immune cells known as macrophages become overly active and begin producing high levels of inflammatory proteins called cytokines. These cytokines, in turn, bind to receptors on the macrophages, stimulating them to produce more cytokines, thus perpetuating the cycle of inflammation that leads to the debilitating symptoms of IBD. Experts have developed a treatment that controls the levels of these cytokines.

New treatment

The research team, led by Liangfang Zhang and Joseph Wang, both professors of chemical and nanoengineering at the University of California, San Diego, designed microscopic robots made of very small particles that chemically bind to green algae cells.

The robots absorb inflammatory cytokines in the intestine, while the green algae use their natural swimming abilities to efficiently distribute the nanoparticles throughout the colon, speeding up the removal of cytokines and helping heal inflamed tissue.

The researchers ensured that the biohybrid microbots met safety standards. The microbots are encased in a liquid capsule with a pH-responsive outer shell. This layer remains intact in acidic environments such as those found in the stomach, but dissolves when neutral pH levels such as those found in the colon are reached, ensuring that the microbots are selectively released where they are needed most.

“We can direct the microrobots to the affected site without affecting other organs, and in this way we can reduce toxicity,” Wang says.

The team gave the capsule orally to mice with inflammatory bowel disease, and the treatment reduced stool bleeding, improved stool consistency, and reduced inflammation in the colon, all without apparent side effects.

The research team is now focusing on testing the microrobot therapy on humans.