Bone formation into surface phosphonylated polymeric implants

Through the use of two animal models, the present study demonstrates the ability of phosphonylated surfaces to bind bone. In one model, surface-treated polypropylene (PP) and polyethylene (PE) were implanted in the medial cortex of the goat tibia. In the second model, surface-treated poly(ether-ether ketone) (PEEK) and carbon fiber-reinforced PEEK (CFR-PEEK) were implanted through both cortices of the goat mandible. Selected rods of all material types were microtextured using crystallization induced microphase separation, a method for the formation of continuous, open-cell microporous surfaces in thermoplastic polymers. Microtextured and smooth rods were phosphonylated, and calcium was subsequently introduced to the phosphonylated surface by incubating the samples in a saturated solution of calcium oxide. For all substrate materials tested, phosphonylation and calcium posttreatment resulted in an increased propensity for bone binding and apposition, as measured by push out test. Microtextured PP, PE, and CFR-PEEK surfaces that were further phosphonylated and calcium treated resulted in test samples with an increased interfacial strength.