Finding a cure for inflammatory bowel disease is a big goal. But the key to achieving it might be to think small.
University of Wisconsin-Madison researchers are developing nanoparticles — particles measuring between 1 and 100 nanometers (one-billionth of a meter) — designed to treat IBD, including Crohn’s disease and ulcerative colitis. (For context: A sheet of paper is about 100,000 nanometers thick.)
Described in a paper in Science Advances, these nanoparticles can fight harmful molecules, called reactive oxygen species (ROS), that can worsen IBD in excessive amounts. They are made from poly(propylene sulfide) — a polymer that can neutralize ROS — and hyaluronic acid, a compatible compound commonly used in medicine.
The nanoparticles — the researchers call them “backpacks” — can be attached to probiotics, which deliver them to the gut.
“Due to the colonizing property of probiotics in colon tissues, the nanoparticles could be delivered to colon tissues by probiotics and released slowly,” says study author Quanyin Hu, PhD, a biomedical engineer and assistant professor at the University of Wisconsin-Madison School of Pharmacy.
This helps give the nanoparticles time to bring the ROS level back down to normal. But that’s only part of the IBD treatment the researchers envision.
The technology builds on a previous development from Hu and his team — a protective probiotic shell coating. The coating, which is about 330 nanometers thick, helps probiotics survive long enough to establish and multiply in the gut.
“The harsh environment of gastric acid and bile salt would kill most probiotics,” Hu says. “Moreover, antibiotics usually used in inflammatory bowel disease treatment also harm probiotic growth.”
Early results are promising, he says. Mice with IBD that received the full treatment — combining the ROS-targeting nanoparticles with the coated probiotics — had fewer IBD symptoms, like less weight loss and colon shortening, than those treated with the encapsulated probiotics alone.
By attacking the disease on multiple fronts — reducing the ROS and improving the balance of gut microbiota — a healthy gut environment could be restored, Hu says. In other words: “[It] might be possible to finally cure inflammatory bowel disease.”
Nanotechnology offers all kinds of unique advantages over traditional IBD treatments, he says. Nanoparticles can be designed to target specific tissues, like colon tissues. And compared to small molecules, they can circulate throughout the body longer, so they have more time to build up and do their job.
The next steps will be to test the treatment in large animals and “to develop a stable formulation that can be stored for a long time and produced in a scalable and economical manner,” Hu says.
Current IBD treatments “can only relieve symptoms,” not cure the disease, he says.
“This study is our first try to fundamentally treat inflammatory bowel disease by recovering a healthy microenvironment in the intestines, and our preliminary data demonstrated that this strategy is delivering promises to pave a new treatment strategy for IBD,” Hu says.