Correlation between bioactivity and structural properties of titanium dioxide coatings grown by atomic layer deposition

► TiO2 was grown on Ti and Si by ALD in the range of the reaction cycles N = 100-2000. ► TiO2 coatings reveal polycrystalline structure at the value of N ≥ 300. ► The TiO2 coatings bioactivity was evaluated by hydroxyapatite forming ability in SBF. ► Amorphous TiO2 coating did not induce the hydroxyapatite growth. ► TiO2 anatase bioactivity was confirmed by the hydroxyapatite forming on its' surfaces.