A team of engineers from the University of California San Diego has created a pill that can release tiny robots, known as microrobots, into the colon to help with inflammatory bowel disease (IBD). In tests on mice, this new approach has been successful in reducing IBD symptoms and promoting the healing of damaged colon tissue without any negative side effects. This treatment is given orally and has shown promising results in the lab.The healing of damaged colon tissue was promoted and symptoms were reduced without causing harmful side effects, according to a recent study. The study, which was published on June 26 in the journal Science Robotics, focused on inflammatory bowel disease (IBD), an autoimmune disorder that affects millions of people worldwide. IBD is characterized by chronic inflammation of the gut and causes severe abdominal pain, rectal bleeding, diarrhea, and weight loss. The condition occurs when immune cells called macrophages become overly activated and produce high levels of pro-inflammatory cytokines, which are proteins that cause inflammation. These cytokines bind to receptors on macrophages, triggering them to produce even more cytokines.Researchers have created a new treatment to control the levels of cytokines that cause inflammation in the gut. The team, led by Liangfang Zhang and Joseph Wang at UC San Diego, designed microrobots made of inflammation-fighting nanoparticles attached to green algae cells. The nanoparticles absorb and neutralize the troublesome cytokines, while the algae’s natural swimming abilities help spread the nanoparticles throughout the gut. This approach breaks the cycle of inflammation that leads to the symptoms of IBD.Nanoparticles are dispersed throughout the colon, speeding up the removal of cytokines to aid in the healing of inflamed tissue. What makes these nanoparticles so effective is their biomimetic design. They are composed of biodegradable polymer nanoparticles that are coated with macrophage cell membranes, allowing them to function as macrophage decoys. These decoys naturally bind to pro-inflammatory cytokines without being triggered to produce more, thus interrupting the inflammatory cycle. “The beauty of this approach is that it’s drug-free – we simply use the natural cell membrane to absorb and neutralize pro-inflammatory cytokines,” explained Zhang. The researchers have made sure that this approach does not have any side effects that could harm the body.Our biohybrid microrobots have passed strict safety standards. The nanoparticles are made of materials that are compatible with the body, and the green algae cells used in our study are approved by the U.S. Food and Drug Administration for consumption.
These microrobots are contained in a liquid capsule with a pH-responsive coating. The coating stays intact in the acidic environment of the stomach, but dissolves once it reaches the neutral pH of the colon. This means that the microrobots are released specifically where they are needed. “We are able to guide the microrobots to the affected area without any issues.”Wang stated that the capsule helps to minimize toxicity by keeping the algae in a liquid phase until they are released. When given orally to mice with IBD, the capsule reduced fecal bleeding, improved stool consistency, reversed IBD-induced weight loss, and reduced colon inflammation without any apparent side effects. The team is now working on moving their microrobot treatment into clinical studies, with the support of the Defense Threat Reduction Agency Joint Science and Technology Office for Chemical and Biological Defense.The project code for this assignment is HDTRA1-21-1-0010.
