Interaction between sulphated macromolecules and hydroxyapatite studied by infrared spectroscopy.

Transmission infrared spectroscopy has been used to study some aspects of the mechanism of binding of chondroitin-4-sulphate to hydroxyapatite. The disappearance of absorption maxima characteristic of the covalently bound sulphate groups indicates that these groups may be involved in bridging the chondroitin sulphate molecule to the crystal lattice of the hydroxyapatite. The technique may be valuable, both in studying the formation of organic films on tooth surfaces and the mechanisms of endogenous mineralisation.