The influence of monosaccharides and related molecules on the crystal morphology of hydroxyapatite (HAP) precipitated from chloride-containing supersaturated solutions has been studied by transmission electron microscopy. Pulse addition of aliquots of CaCl₂ to Na₂HPO₄ solutions resulted in the formation of plate-like HAP crystals. In contrast, the presence of the monosaccharides D-glucose, D-galactose, D-mannose, glucuronic acid, N-acetyl glucosamine and D-fructose (phosphate:additive = 6:1) induced the precipitation of needle-shaped HAP crystals elongated along the c-axis. Other molecules, such as sorbitol and 1,2-butanediol, also showed this morphological effect. The order of decreasing aspect ratios was; sorbitol = 1,2-butanediol (25:1)> fructose (20:1)> glucose = galactose = mannose = glucuronic acid = N-acetyl glucosamine (10:1). Expression of the needle-like morphology is discussed in terms of kinetic factors involving nucleation and growth. The former is dependent on the exclusion of Cl^- from HAP nuclei due to additive interactions with an amorphous calcium phosphate precursor phase. The latter is related to the strength of additive binding with the subsequent development of {100} HAP crystal faces.

Item Type:	Refereed Article
Keywords:	additive binding, crystal morphology, hydroxyapatite, kinetic factors, onosaccharides
Research Division:	Biological Sciences
Research Group:	Biochemistry and cell biology
Research Field:	Structural biology (incl. macromolecular modelling)
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the biological sciences
UTAS Author:	Heywood, BR (Professor Brigid Heywood)
ID Code:	104429
Year Published:	1993
Web of Science® Times Cited:	91
Deposited By:	Research Division
Deposited On:	2015-11-11
Last Modified:	2015-11-12
Downloads:	0