Scientists have discovered a previously unrecognized way that degradation can occur in silicone-urethane plastics that are often considered for use in medical devices. Their study, published in ACS' journal Macromolecules, could have implications for device manufacturers considering use of these plastics in the design of some implantable devices, including cardiac defibrillation leads.
Kimberly Chaffin, Marc Hillmyer, Frank Bates and colleagues explain that some implanted biomedical devices, such as pacemakers and defibrillators, have parts made of a plastic consisting of polyurethane and silicone. While these materials have been extensively studied for failure due to interaction with oxygen, no published study has looked at interaction with water as a potential failure mechanism in this class of materials. In a cardiac lead application, these materials may be used as a coating on the electrical wires or "leads" that carry electric current from the battery in the device to the heart. Surgeons implant pacemakers in 600,000 people worldwide and defibrillators in 100,000 people in the United States each year. Since these implants must function reliably for years, the scientists wanted to determine whether the plastic material was suitable for long-term implants.
Their laboratory tests, including accelerated aging of the materials under conditions that simulated the inside of the human body, found indications that the material begins to break down within 3-6 years. "By making the conclusions of this novel, scientific research public in a respected peer-reviewed journal, device manufacturers may now consider these important findings in their device designs," says Chaffin, distinguished scientist and lead author of the manuscript.
American Chemical Society: http://www.acs.org
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Popular myth has long credited New York's soft water for the city's irresistibly crusty, chewy bagels. But the chemistry behind a superior bagel is more complicated.
A powerful earthquake in Italy killed hundreds of people—and set in motion a legal battle and scientific debate that has kept seismologists on edge
The Large Hadron Collider is smashing protons at the highest energy ever attempted - but they are only test collisions, as the LHC continues to gear up its second run.
Separate sections of one of New Zealand's biggest faults appear to have ruptured simultaneously in the past, suggesting a huge quake there is possible in the future
In a central London pub, a young bearded physicist is demonstrating how to build a model of the universe from plastic Lego bricks. Clue: you need a lot of them.
Kim Jong-un's nuclear ambitions aren't the only reason a nuke-free world is looking more like a pipe dream. All nuclear states are currently upgrading their arsenals
A new study shows many animals can make their own sunscreen, which could help humans down the line
The more scientists examine H2O, the stranger it starts to seem. Water bends all the rules – but if it didn’t, ice would sink and firefighters’ hoses would be useless
CERN’s huge particle accelerator is working its way toward full operation and a new phase of exploration. But it is not only the accelerator that has been upgraded – the particle detectors have some new tricks too
A magnitude 7.3 earthquake strikes eastern Nepal, two weeks after a devastating quake that killed more than 8,000 people.