Hydrogel could stop medical implants being rejected

Engineers from the University of Washington have developed a synthetic hydrogel which they claim could prevent medical implants being rejected by the human body.

After an implant, the body usually creates a protein wall around the medical device, cutting it off from the rest of the body. Scientists call this barrier a collagen capsule. If a device such as an artificial valve or an electrode sensor is blocked off from the rest of the body, it usually fails to work. The new material created by the Washington team is 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. The Washington team tested the hydrogel in the bodies of mice over a period of three months. After this time, they found that collagen was loosely and evenly distributed in the tissue around the polymer, suggesting that its presence wasn't even detected. "Scientists have tried many materials, and with no exception, said researcher Shaoyi Jiang. "This is the first non-porous, synthetic substance demonstrating that no collagen capsule forms, which could have positive implications for implantable materials, tissue scaffolds and medical devices."