As long as there have been medical devices ― mechanisms ranging from stents and tubing to catheters and implants ― patients have faced the risk of infections and blood clots.
That's because varying types of artificial surfaces can be sticky when placed in the body. Scientists refer to this "stickiness" as the frictional coefficient of the material. In everyday terms, it means that bacteria or blood molecules flowing by in the bloodstream tend to adhere to surfaces more so than to the body's tissues. That's a big problem when it happens to patients, and it's difficult to clear up. Device-related infections or mats of bacteria called biofilms, can spread at a high risk to patients. When blood clots on surfaces ― what's called a thrombosis ― heart attack or stroke is always a risk.
But now a research team thinks it may have a way to decrease these risks: a hydrogel lining that will allow molecules to slip by without sticking.
This research team consists of Mayo Clinic researcher Christoph Nabzdyk, M.D., as well as colleagues from the Massachusetts Institute of Technology (the lab of Xuanhe Zhao, Ph.D.) and Massachusetts General Hospital, and researchers from China.
Dr. Nabzdyk is a cardiac anesthesiologist and intensivist who works with specialized catheters and other cardiovascular devices in Mayo Clinic’s ICUs. He is the co-lead author of recently published findings that show the team's "ultrathin and robust" hydrogel prevented clotting and bacterial presence in lab and animal experiments. In a controlled experiment with tubing, 40% of the blood in contact with the uncoated surface clotted, compared to just 6% of the blood in contact with hydrogel-coated tubing. In another test with an animal model, it took 60% longer for an ultranarrow silicone tube to block when it was coated with the hydrogel than when it was uncoated.
The researchers say their findings could serve as a proof of concept for future studies on hydrogel-based device coatings.
This research was funded by the National Science Foundation, the Office of Naval Research, and the U.S. Army Research Office.