Researchers at the North Carolina State University, Raleigh, have successfully coated polymer implants with a bioactive film that, they say should improve the success rate of the implants, typically used in spinal surgeries.
The polymer contained in these implants, called Polyetheretherketone (PEEK), tends to not bond well with bone or other tissues in the body, which can result in the implant rubbing against surrounding tissues and can lead to medical complications including the need for additional surgeries.
Dr. Afsaneh Rabiei, an associate professor of mechanical and aerospace engineering and lead author of a paper on the research, said “The challenge was that these coatings need to be heated to 500 degrees Celsius, but the polymer melts at 300 C. We’ve finally solved the problem.”
Their first step in the new technique was coating the implant with a thin film of yttria-stabilized zirconia (YSZ). They then applied a coating of hydroxyapatite, a calcium phosphate that bonds well with bone, and heating the hydroxyapatite layer using microwaves. The YSZ layer acts as a heat shield and prevents the PEEK from melting. Meanwhile, the heat gives the hydroxyapatite a crystalline structure that makes it more stable in the body, meaning that the calcium phosphate will dissolve more slowly and promoting bonding with surrounding bone.
Their research was published online in the Journal of Biomedical Materials Research: Part A.
