Single-step immobilization of hydroxyapatite on fluoropolymer surfaces for enhanced cell adhesion

Herein, we report a single-step immobilization of hydroxyapatite (HAp) on the surface of poly(vinylidene fluoride) copolymer. This method utilizes the ability of fluoropolymer to undergo a limited swelling in acetone/water mixture followed by an entrapment of HAp on its surface. We found that while acetone/water ratio does not affect the thickness of HAp-containing layer, an increase in acetone content results in higher amounts of calcium and phosphorus found in modified area. HAp immobilization not only improved the hydrophilicity of the poly(vinylidene fluoride) copolymer surface but also contributed to enhanced cell adhesion (0.8 ± 0.4 % for the fluoropolymer surface vs. 86.9 ± 9.1 % for the modified fluoropolymer surface) and viability (increased by up to 30 %). Overall, this method represents a potent strategy for the modification of fluoropolymers which allows for the fabrication of bioactive implants using standard laboratory equipment.