New medical implants from biomaterials science

Jul 4 2007

A world leader in medical implants calls for a rethink in our approach to building medical implants.

Currently so-called biomaterials are chosen because they are reasonably successful at hiding from the body's immune system, and are consequently not rejected. All the same, within a month of implanting them, the body isolates implants by wrapping them in a collagenous, avascular sac. Materials are considered to be 'biocompatible' if this sac is not too thick.

"That's not very clever," says Professor Buddy Ratner, Director of the University of Washington Engineered Biomaterials, in Seattle, USA. In a commentary published in Polymer International, he says that it is time to take a more intelligent approach.

Rather than building implants out of materials that try to hide from the body's systems, he believes that we should be creating them from materials that are specifically designed to engage with biological processes. This could take the form of materials made with specifically sized pores that encourage small blood vessels to actively grow through the implant, or implants coated with DNA that specifically prevents formation of the collagenous capsule.

Both of these let the implant and the body actively work together, rather than simply try to prevent them fighting against each other.

Ratner looks forward to an exciting future. "These sorts of ideas will lead to a new biomaterials science that will permit us to make materials for medical devices that function better, last longer, encourage healing and provide enhanced patient satisfaction," says Ratner.