Dose-dependent modulation of octacalcium phosphate crystal habit by amelogenins

In vitro studies on interactions between amelogenins and calcium phosphate crystals are critical for elucidating biomineralization mechanisms of tooth enamel. This work was aimed at investigating the effects of native porcine amelogenins on octacalcium phosphate (OCP) crystal growth in a gelatin gel . We prepared OCP mineral discs hy circulating calcium and phosphate soluti ons on the opposite ends of the gels loaded with 0-2% amelogenin for one we ek. A dose-dependent modulation of OCP crystal habit lay amelogenins a;as o bserved by scanning electron microscopy. While the incorporation of 0.125, 0.25, or 0.5% amelogenins showed no significant effect on the crystal morph ology;, in the presence of 1 and 2% amelogenins, the crystals were remarkab ly longer, having an average aspect 3-5 times greater than that of those fo rmed in the control gels. Transmission electron microscopy and atomic force microscopy suggested that amelogenin assemblies selectively blocked b-axia l development, resulting in the c-axial elongation of OCP crystals.