How Your Body Reacts To A Medical Implant Depends On Age, Researchers Want To Know Why

Aug 8, 2017

Every year in the U.S., 200,000 people get pacemakers, 600,000 get knee replacements and 2.5 million have surgery to implant artificial eye lenses to fix cataracts. But the medical community knows little about how the aging process affects these implantable medical devices.

Bryan Brown wants to change that.

He’s a professor of bioengineering at the University of Pittsburgh, and he’s trying to figure out how to harness the immune system’s natural inflammatory response to better integrate these devices into the body.

In his lab at the McGowan Institute for Regenerative Medicine, researchers develop materials for different surgical applications and observe how the body responds using animal trials.

Polypropylene surgical mesh is often used to repair hernias and pelvic organ prolapse.
Credit Liz Reid / 90.5 WESA

“Think about some of the cells that come in there they clean up debris, they kill bacteria, those are important functions,” said Brown. “And so any time we have an implant we create a surgical injury, so we have inflammation whether we want it or not.”

In young mammals, whether mice or humans, the inflammatory response is strong and predictable, and Brown said the way the body responds to implants is important to how they heal.

“Inflammation can actually be productive in terms of helping an implant to integrate within the body,” Brown said.

But in older mammals, including those people most likely to wind up with hip replacements and pacemakers, the response becomes less effective.

“We think that there is something inherent in that inflammatory process, something that's different about the inflammation that happens following the implantation of a medical device in an aged animal versus young,” Brown said.

Brown said figuring that out could help researchers find ways make devices work better in the body.

Which Brown said is important because, while we are living longer, we aren’t necessarily staying healthy longer. Couple that fact with advances in medical technology that could bring new implantable devices to market, the demand for such devices is likely to increase.

“Understanding how the body interfaces with those those materials, and the types of materials that are used in implants, I think will be very important,” Brown said.