Tiny nanoparticles might be able to make a big difference in plastic artificial hips.
Nanoparticles are being used in diamondlike coatings on polymer-metal alloys for artificial hips, said Jack Lemons, a researcher with the University of Alabama-Birmingham who spoke at the Materials, Medicine and Nanotechnology Summit, held Oct. 2-5 in Cleveland.
Currently, new versions of cross-linked polyethylene are competing with ceramic and metal parts in the hip-replacement field, which is expected to grow as baby boomers age.
``Some people are staying more active at an older age, while other people are becoming more obese,'' Lemons said.
The hip-replacement industry first used acrylic as a replacement for metal in the 1960s and 1970s. By the 1980s, ultrahigh-molecular-weight PE was being used in conjunction with metal.
UHMW PE was gamma-radiated for sterility purposes, which sometimes broke down the properties of the material.
Nanotechnology could offer big improvements.
``We're going from the device level to the subatomic level in designing parts,'' he said.
ASM International - a Novelty, Ohio, materials science trade group that sponsored the event - also highlighted several recent medical plastic developments:
* Carbon-fiber-reinforced polyetheretherketone used in implant parts by Invibio Inc. of Greenville, S.C. When used with ceramic counterfaces, the reinforced PEEK produces less wear than similar parts made of UHMW PE.
* Fluropolymer-coated medical wire used in devices by Sandvik AB of Sandviken, Sweden. The coating is more consistent and performs better than standard electrostatic fluoropolymer spray coatings, officials said.
* Two biopolymers - polydioxanone and elastin - used in an electro-spun material for replacement arteries by Virginia Commonwealth University in Richmond, Va. The blend degrades more slowly and causes fewer adverse reactions than other materials, officials said. The new material could help a patient regenerate a new artery within six months of surgery, ASM said.