Abstract: The aim of this study was to reconstruct surface porous structure with hundreds of micrometers and then bio-mineralize Sr-doped Calcium Phosphate (Sr-doped CaP) on Polyetheretherketone (PEEK) profile to enhance its bioactivity. A surface porous structure was prepared on PEEK profile by embedding and acid-etching of SiO2 particles as porogen (SP-PEEK). Then the Sr-doped CaP was further decorated on the porous surface after sulfonation, introduction of Sr-doped CaP crystal seeds and bio-mineralization in 1.5 times simulated body fluid (BSSP-PEEK-CaP/Sr). It was feasible to reconstruct the surface porous structure with hundreds of micrometers on PEEK profile by the present method without damaging its mechanical properties. The Sr-doped CaP crystal seeds effectively promoted the bio-mineralization of bio-inertness PEEK. All as-prepared PEEK did not inhibit the proliferation of cells. ALP of bio-mineralized groups was significantly increased than that of the other groups. The BSSP-PEEK-CaP/Sr obviously affected the morphology and promoted the adhesion and spreading of cells. As a result, the cyto-biocompatibity and bioactivity of PEEK were improved after bio-mineralization. Sr-doped CaP on PEEK most likely was beneficial for cells, which was associated with the increasing of the hydrophilicity on PEEK. This study provided a candidate method to improve the osteogenesis of PEEK implants. 

Key words: PEEK, surface porous structure, bio-mineralization, bioactivity, Sr-doped Calcium phosphate