Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Better Joint Replacements: Titanium Coating with Protein “Flower Bouquet” Nanoclusters Strengthens Implant Attachment

Georgia Tech research technician Kellie Templeman (left) and former graduate student Tim Petrie display a piece of titanium coated with a bio-inspired polymer that enhances bone formation around the metal after implantation. (Credit: Gary Meek)
Georgia Tech research technician Kellie Templeman (left) and former graduate student Tim Petrie display a piece of titanium coated with a bio-inspired polymer that enhances bone formation around the metal after implantation. (Credit: Gary Meek)

Abstract:
Researchers have developed an improved coating technique that could strengthen the connection between titanium joint-replacement implants and a patient's own bone. The stronger connection — created by manipulating signals the body's own cells use to encourage growth — could allow the implants to last longer.

Better Joint Replacements: Titanium Coating with Protein “Flower Bouquet” Nanoclusters Strengthens Implant Attachment

Atlanta, GA | Posted on August 20th, 2010

Implants coated with "flower bouquet" clusters of an engineered protein that mimics the body's own cell-adhesion material fibronectin made 50 percent more contact with the surrounding bone than implants coated with protein pairs or individual strands. The cluster-coated implants were fixed in place more than twice as securely as plugs made from bare titanium — which is how joints are currently attached.

Researchers believe the biologically-inspired material improves bone growth around the implant and strengthens the attachment and integration of the implant to the bone. This work also shows for the first time that biomaterials presenting biological sequences clustered together at the nanoscale enhance cell adhesion signals. These enhanced signals result in higher levels of bone cell differentiation in human stem cells and promote better integration of biomaterial implants into bone.

"By clustering the engineered fibronectin pieces together, we were able to create an amplified signal for attracting integrins, receptors that attached to the fibronectin and directed and enhanced bone formation around the implant," said Andrés García, professor in Georgia Tech's Woodruff School of Mechanical Engineering and the Petit Institute for Bioengineering and Bioscience.

Details of the new coating were reported in the August 18 issue of the journal Science Translational Medicine. The research was supported by the National Institutes of Health, the Arthritis Foundation, and the Atlanta Clinical and Translational Science Institute through the Georgia Tech/Emory Center for the Engineering of Living Tissues.

Total knee and hip replacements typically last about 15 years until the components wear down or loosen. For many younger patients, this means a second surgery to replace the first artificial joint. With approximately 40 percent of the 712,000 total hip and knee replacements in the United States in 2004 performed on younger patients 45-64 years old, improving the lifetime of the titanium joints and creating a better connection with the bone becomes extremely important.

In this study, Georgia Tech School of Chemistry and Biochemistry professor David Collard and his students coated clinical-grade titanium with a high density of polymer strands — akin to the bristles on a toothbrush. Then, García and Tim Petrie — formerly a graduate student at Georgia Tech and currently a postdoctoral fellow at the University of Washington — modified the polymer to create three or five self-assembled tethered clusters of the engineered fibronectin, which contained the arginine-glycine-aspartic acid (RGD) sequence to which integrins binds.

To evaluate the in vivo performance of the coated titanium in bone healing, the researchers drilled two-millimeter circular holes into a rat's tibia bone and pressed tiny clinical-grade titanium cylinders into the holes. The research team tested coatings that included individual strands, pairs, three-strand clusters and five-strand clusters of the engineered fibronectin protein.

"To investigate the function of these surfaces in promoting bone growth, we quantified osseointegration, or the growth of bone around the implant and strength of the attachment of the implant to the bone," explained García, who is also a Woodruff Faculty Fellow at Georgia Tech.

Analysis of the bone-implant interface four weeks later revealed a 50 percent enhancement in the amount of contact between the bone and implants coated with three- or five-strand tethered clusters compared to implants coated with single strands. The experiments also revealed a 75 percent increase in the contact of the three- and five-strand clusters compared to the current clinical standard for replacement-joint implants, which is uncoated titanium.

The researchers also tested the fixation of the implants by measuring the amount of force required to pull the implants out of the bone. Implants coated with three- and five-strand tethered clusters of the engineered fibronectin fragment displayed 250 percent higher mechanical fixation over the individual strand and pairs coatings and a 400 percent improvement compared to the unmodified polymer coating. The three- and five-cluster coatings also exhibited a twofold enhancement in pullout strength compared to uncoated titanium.

Georgia Tech bioengineering graduate students Ted Lee and David Dumbauld, chemistry graduate students Subodh Jagtap and Jenny Raynor, and research technician Kellie Templeman also contributed to this study.

This work was partly funded by Grant No. R01 EB004496-01 from the National Institutes of Health (NIH) and PHS Grant UL1 RR025008 from the Clinical and Translational Science Award program, NIH, National Center for Research Resources. The content is solely the responsibility of the principal investigator and does not necessarily represent the official view of the NIH.

####

About Georgia Tech
The Georgia Institute of Technology is one of the nation's top research universities, distinguished by its commitment to improving the human condition through advanced science and technology.

For more information, please click here

Contacts:
Research News & Publications Office
Georgia Institute of Technology
75 Fifth Street, N.W., Suite 314
Atlanta, Georgia 30308 USA

Media Relations Contacts:
Abby Vogel Robinson

404-385-3364
or
John Toon


Writer:
Abby Vogel Robinson
404-385-3364

Copyright © Georgia Tech

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014

ECHA Planning Workshop on Regulatory Challenges in the Risk Assessment of Nanomaterials April 16th, 2014

Lumerical files a provisional patent that extends the standard eigenmode expansion propagation technique to better address waveguide component design. Lumerical’s EME propagation tool will address a wide set of waveguide applications in silicon photonics and integrated optics April 16th, 2014

Nanomedicine

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Nanobiotix Appoints Thierry Otin as Head of Manufacturing and Supply April 15th, 2014

PAM-XIAMEN Offers UV LED wafer April 15th, 2014

Nanocrystalline cellulose modified into an efficient viral inhibitor April 15th, 2014

Discoveries

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scientists observe quantum superconductor-metal transition and superconducting glass: A team including MIPT physicist observed quantum superconductor-metal transition and superconducting glass April 16th, 2014

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Announcements

UT Arlington physicist creates new nanoparticle for cancer therapy April 16th, 2014

Relieving electric vehicle range anxiety with improved batteries: Lithium-sulfur batteries last longer with nanomaterial-packed cathode April 16th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Energy Research Facility Construction Project at Brookhaven Lab Wins U.S. Energy Secretary's Achievement Award April 16th, 2014

Nanobiotechnology

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Biologists Develop Nanosensors to Visualize Movements and Distribution of Plant Stress Hormone April 15th, 2014

In latest generation of tiny biosensors, size isn't everything: UCLA researchers overturn conventional wisdom on nanowire-based diagnostic devices April 11th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

NanoNews-Digest
The latest news from around the world, FREE







  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE