Engineered Biomaterial Could Improve Success of Medical Implants

Expensive, state-of-the-art medical devices and surgeries often are thwarted by the body's natural response to attack something in the tissue that appears foreign. Now, University of Washington engineers have demonstrated in mice a way to prevent this sort of response.

The UW researchers created a synthetic hydrogel that fully resists the body's natural attack response to foreign objects. Medical devices such as artificial heart valves, prostheses and breast implants could be coated with this polymer to prevent the body from rejecting an implanted object.

Team implanted the polymer substance into the bodies of mice. The substance is known as a hydrogel, a flexible biomedical material swollen with water. It's made from a polymer that has both a positive and negative charge, which serves to deflect all proteins from sticking to its surface. Scientists have found that proteins appearing on the surface of a medical implant are the first signs that a larger collagen wall will form.

After three months, Jiang and his team found that collagen was loosely and evenly distributed in the tissue around the polymer, suggesting that the mice bodies didn't even detect the polymer's presence. UW researchers and others have worked for nearly 20 years to find a way to help the body accept implants. In 1996, the National Science Foundation-funded UW Engineered Biomaterials (UWEB) research center opened at the UW, with Ratner serving as director. Since that time, researchers have been trying to make a material that is invisible to the body's immune response and could eliminate the body's negative reaction to medical implants. Now, nearly two decades years later, engineers have found the "perfect" substance.