Immobilization of hydroxyapatite on polyetherketoneketone surfaces for improved cell adhesion.

• A method for hydroxyapatite immobilization on PEKK surfaces was suggested. • Up to 29 ± 3 % of PEKK surface was coated with hydroxyapatite. • Maximum Ca and P content of 5.3 ± 0.1 and 0.5 ± 0.1 at. % was achieved. • Hydroxyapatite immobilization improved cell adhesion to PEKK surface. A novel approach for the immobilization of hydroxyapatite (HAp) on polyetherketoneketone (PEKK) surface was suggested. HAp immobilization was performed in two steps. On the first step, PEKK surface was swelled in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) vapor. Then, the treated sample was placed in HAp water suspension. Up to 29 ± 3 % of the PEKK surface was coated with HAp. The maximum calcium and phosphorus content on the surface of the modified samples was found at 5.3 ± 0.1 and 0.5 ± 0.1 at. %, respectively. Despite the confirmed HAp immobilization, the hydrophobic character of the PEKK surfaces was preserved. HAp immobilization resulted in the enhanced adhesion of multipotent stem cells to the PEKK surfaces: the number of the adhered cells and cell-covered sample area increased nearly 10-fold and 25-fold, respectively. Thus, the suggested approach of HAp immobilization allows improving cell adhesion to PEKK-based surfaces. [ABSTRACT FROM AUTHOR]