Microscopic titanium particles weaken the bonding of hip, knee, and other joint replacements, according to research published online in Proceedings of the National Academy of Sciences by researchers at the University of California, San Diego (UCSD) School of Medicine and the Jacobs School of Engineering. The team demonstrated that titanium implants are safe in large blocks, but at the microscopic level, wear and tear can generate micrometer-sized particles.
"As replacement joints are becoming increasingly common in aging populations, our results explain how such devices fail and suggest that improvements should be made in artificial joint design," said the study's senior author K.L. Paul Sung, Ph.D., UCSD professor of orthopedic surgery and adjunct professor of cellular bioengineering.
The team measured how titanium particles affected the bonding strength of pins implanted in rat thighs. The pins were shown to come out more easily when the titanium particles were present, with the smallest and largest particles causing the greatest weakening. The researchers demonstrated how different-sized titanium particles affected bone-building cells called osteoblasts and bone-destroying cells called osteoclasts. Microscopic studies revealed osteoblasts did not form proper adhesions, with small- and medium-sized titanium particles concentrated inside cells. Increased production of the protein RANKL by osteoblasts recruited and activated osteoclasts at the insertion sites, further weakening the bone. Larger titanium particles also activated metalloproteinases, which chop up the extracellular matrix that holds cells together.
Page: 1 Related biology news :1
Contact: Sue Pondrom
University of California - San Diego
. Minnesota and Michigan reseachers discover new insights for antibiotic drug development2
. Landfills, chemical weapon debris possibly a good match, computer model suggests3
. Scientists develope a new model of artificial canine skin4
. Flexible electronics could find applications as sensors, artificial muscles5
. Researchers create artificial enzyme that mimics the bodys internal engine6
. Progress toward artificial photosynthesis?7
. Carnegie Mellon researcher proposes development of artificial cells to fight disease8
. Genetically altered cells may help artificial skin fight infection9
. Bacteria for better ice cream and artificial snow no longer depends on trek to poles10
. An artificial cornea is in sight, thanks to biomimetic hydrogels11
. Stimulation of the semicircular canals can artificially control human walking and balance