Making implants bond to the bone

Polyether ether ketone (PEEK), used to make polymer implants for spinal or other bone injury, doesn’t bond well with bone. Bioactive coating can improve bonding, but the coating needs to be heated to 500 degrees C, a temperature that melts PEEK. Research scientists at North Carolina State University (NCSU) have discovered a two-step process to bring the bioactive coating and implant together. In the first step, a new technique coats the implant with a thin film of yttria-stabilized zirconia, which acts as a heat shield to prevent the polymer from melting. In the second step, researchers heat a calcium phosphate compound that bonds well with bone, which seals it to the implant. The calcium phosphate dissolves slowly, allowing bone and implant to successfully grow together. “We have received funding from the National Institutes of Health to proceed with animal testing,” says Dr. Afsaneh Rabiel, associate professor of mechanical and aerospace engineering.