Figure 1.

Adsorption isotherms of BSA onto octacalcium phosphate (OCP) plotted as adsorption amount as a function of initial BSA concentration (A) and adsorption amount per unit area of OCP as a function of BSA equilibrium concentration (B) in solutions containing 1.0 mM Pi ion and 1.5 or 3.0 mM Ca²⁺ (Ca1.5P1.0 and Ca3.0P1.0, respectively). Mean values were obtained from three independent experiments (n = 3). Significant difference (p < 0.01) for 0.20, 0.25, 0.75, 1.0 and 1.5 mg·mL⁻¹ BSA in ^aCa3.0P1.0 and ^bCa1.5P1.0 solution; ^cSignificant difference (p < 0.01) for 0.20, 0.25 and 1.0 mg·mL⁻¹ BSA in Ca3.0P1.0; ^dp < 0.01 significantly difference from 0.20 and 0.25 mg·mL⁻¹ BSA in Ca1.5P1.0; ^eSignificant difference (p < 0.01) from 0.20 and 1.0 mg·mL⁻¹ BSA in Ca3.0P1.0; ^fp < 0.01 significant difference for 0.20, 1.0 and 1.5 mg·mL⁻¹ BSA in Ca1.5P1.0. ^gp < 0.01 significant difference from 0.10 and 1.5 mg·mL⁻¹ BSA in Ca3.0P1.0; ^hp < 0.01 significant difference for 1.5 mg·mL⁻¹ BSA in Ca1.5P1.0; **p < 0.01 significant difference between Ca1.5P1.0 and Ca3.0P1.0 solution at each BSA concentration. Dashed line indicates the adsorption isotherm of BSA onto OCP under saturation conditions with respect to OCP at 37 °C and pH 7.4 reported by Suzuki et al. [25], and is plotted using adsorption constants obtained from previous reports [25] based on the Langmuir equation (Equation (2)).