Strontium ranelate incorporated 3D porous sulfonated PEEK simulating MC3T3-E1 cell differentiation

Polyetheretherketone (PEEK) has been used as an implant material because it has similar mechanical properties to natural bone. However, inferior osseointegration and bioinertness hamper the clinical application of PEEK. In this study, the surfaces of sulfonated three-dimensional (3D) PEEK porous structures were loaded with different concentrations of strontium ranelate, a compound commonly used in the treatment or prevention of osteoporosis by promoting bone formation and inhibiting bone resorption. Field-emission scanning electron microscopy was used to characterize the topography of the structures, elemental carbon, oxygen and strontium contents were measured by X-ray photoelectron spectroscopy, and surface zeta potentials and water-contact angle were also measured. The results indicated that strontium ranelate was successfully loaded onto the 3D porous structures. In vitro cellular results showed that strontium ranelate-treated sulfonated PEEK (SP-SR) strengthened the adhesion of MC3T3-E1 cells. The activity of alkaline phosphatase, collagen secretion and extracellular matrix mineralization deposition of MC3T3-E1 cells were also improved on the surface of SP-SR. These results indicate that SP-SR could serve a new implant candidate for surgical treatment.