AVS 46th International Symposium
    Biomaterial Interfaces Group Thursday Sessions
       Session BI-ThM

Invited Paper BI-ThM7
Kinetics and Interfacial Energy Studies of Biomineralization

Thursday, October 28, 1999, 10:20 am, Room 613/614

Session: Biomineralization
Presenter: G.H. Nancollas, State University of New York, Buffalo
Authors: G.H. Nancollas, State University of New York, Buffalo
W. Wu, State University of New York, Buffalo
Correspondent: Click to Email
The ability of surfaces to nucleate minerals such as the calcium phosphates is important in a wide range of biological events. The kinetics of crystallization and dissolution of the mineral surfaces has received considerable attention from the point of view of parameters such as solution composition, ionic strength, pH, temperature, and solid surface characteristics. However, a factor which is usually ignored in discussions of such induced crystallization reactions is the surface free energy of the nucleus/substratum interface. The Constant Composition method is especially useful for investigating the mechanisms of these reactions and surface free energies, measured using thin layer wicking methods can be used to corroborate crystal growth and dissolution mechanisms determined from kinetics experiments. Kinetic studies have been made using calcium phosphate phases such as dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), hydroxyapatite (HAP), and fluorapatite (FAP). The much smaller interfacial tensions of OCP and DCPD in contact with water as compared with those of HAP and FAP support the widely held suggestion that the former phases are precursors in HAP and FAP biomineralization. On substrata consisting of minerals, polymers or typical implant materials such as the titanium oxides, the ability of the surfaces to nucleate calcium phosphate minerals is closely related to the magnitude of the interfacial energies.