Engineers at University of California-San Diego have created a pill that releases microrobots into the colon to treat inflammatory bowel disease (IBD). This oral treatment has been successful in mice, reducing IBD symptoms and healing colon tissue without toxic side effects.
The study was published on June 26 in Science Robotics. IBD causes chronic gut inflammation, severe pain, bleeding, diarrhea, and weight loss due to overactive immune cells producing excessive inflammatory proteins.
Researchers at UC San Diego have developed a treatment that effectively controls cytokine levels using engineered microrobots. Led by professors Liangfang Zhang and Joseph Wang, the team created microrobots by combining inflammation-fighting nanoparticles with green algae cells. These microrobots distribute nanoparticles throughout the colon, absorbing and neutralizing pro-inflammatory cytokines.
The nanoparticles, designed with biomimetic properties using biodegradable polymer coated with macrophage cell membranes, act as decoys. They bind cytokines without triggering further inflammation, breaking the cycle and aiding tissue healing.
“The beauty of this approach is that it’s drug-free—we use natural cell membranes to absorb and neutralize pro-inflammatory cytokines,” explained Zhang. The researchers ensured safety by using biocompatible materials for the nanoparticles and FDA-approved green algae cells.
The microrobots, enclosed in a pH-responsive capsule, survive stomach acid but are released in the colon where needed. This targeted delivery minimizes toxicity and effectively directs treatment to the inflamed area, keeping the algae functional until release.
The capsule was given orally to mice with IBD. It reduced bleeding, improved stool consistency, reversed weight loss, and reduced colon inflammation, with no observed side effects. The team is now preparing to move their microrobot treatment into clinical trials.
Journal reference:
- ZHENGXING LI, YAOU DUAN, et al., Biohybrid microrobots regulate colonic cytokines and the epithelium barrier in inflammatory bowel disease. Science Robotics. DOI: 10.1126/scirobotics.adl2007.