Microrobot-packed pill shows promise for treating inflammatory bowel disease in mice

Engineers at the University of California San Diego have developed a pill that releases microscopic robots, or microrobots, into the colon to treat inflammatory bowel disease (IBD).

The experimental treatment, given orally, has shown success in mice. It significantly reduced IBD symptoms and promoted the healing of damaged colon tissue without causing toxic side effects.

It occurs when immune cells known as macrophages become overly activated, producing excessive levels of inflammation-causing proteins called pro-inflammatory cytokines. These cytokines, in turn, bind to receptors on macrophages, triggering them to produce more cytokines, and thereby perpetuating a cycle of inflammation that leads to the debilitating symptoms of IBD.

Now, researchers have developed a treatment that successfully keeps these cytokine levels in check. A team led by Liangfang Zhang and Joseph Wang, both professors in the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at UC San Diego, engineered microrobots composed of inflammation-fighting nanoparticles chemically attached to green algae cells.

The nanoparticles absorb and neutralize pro-inflammatory cytokines in the gut. Meanwhile, the green algae use their natural swimming abilities to efficiently distribute the nanoparticles throughout the colon, accelerating cytokine removal to help heal inflamed tissue.

What makes these nanoparticles so effective is their biomimetic design. They are made of biodegradable polymer nanoparticles coated with macrophage cell membranes, allowing them to act as macrophage decoys. These decoys naturally bind pro-inflammatory cytokines without being triggered to produce more, thus breaking the inflammatory cycle.