New Titanium Coating Improves Joint Replacements

Tag : Coating Material

For that reason, Garcia engineered a much longer region of the sametype of fibronectin that included the RGD peptide sequence as wellas new sections also known to have sites that participate inintegrin binding.
To evaluate the in vivo performance of the coated titanium in bonehealing, chemists Raynor and Collard coated the surfaces of tinyclinical-grade titanium cylinders with the polymer brushes. Thenengineers Petrie and Garcia modified them with peptide sequences.
Two-millimeter circular defects were drilled into a rat's tibiabone and the cylinders were pressed into the holes. The researcherstested three types of coatings: uncoated titanium, titanium coatedwith the RGD peptide and titanium coated with different densitiesof the engineered fibronectin fragment.
To investigate the function of these novel surfaces in promotingbone growth, the researchers quantified osseointegration, or thegrowth of bone around the implant and strength of the attachment ofthe implant to the bone.
Analysis of the bone-implant interface four weeks later revealedextensive and contiguous bone matrix and a 70 percent enhancementin the amount of contact between the implant and bone with thetitanium implants coated with the engineered fibronectin fragmentover the uncoated or RGD-coated titanium.
Garcia and Petrie tested the fixation of the implants by measuringthe amount of force required to pull the implants out of the bone.The study showed significantly higher mechanical fixation of theimplants coated with the engineered fibronectin fragment over theimplants with the other coating and uncoated titanium.
In addition to total joint replacements, Garcia is studying how tofill large gaps between bones, which sometimes occur after atraumatic injury or tumor removal.
"We are developing a strategy to present peptides that encouragethe surrounding bone to grow in and fill in around the gap," saidGarcia.
By improving communication with the body's cells, Garcia cancontrol the integration and healing response of the body to anyimplanted device. Currently, most become encapsulated by a collagensheath, which affects the performance and long-term viability ofthe device. Garcia aims to use these biomaterials to help integratedevices implanted in the body.