Formation of Urinary Stones in Vitro: Growth of Calcium Oxalate on Spherulites of Calcium Phosphate in Gel

Urinary stones are commonly of mixed crystalline composition. Calcium phosphate (CaP), mostly as hydroxyapatite (HAP), has been found to occur in the majority (>75%) of stones containing calcium oxalate (CaOx) as the main component, eg 1, 2. This observation led several authors to suggest that heterogeneous nucleation of CaOx crystal phases on CaP may be an important etiological factor in the genesis of calcium containing stones2-4. Meyer et al 5, Koutsoukos et al 6 and Campbell et al 7 demonstrated epitaxial growth of CaOx on HAP in inorganic solutions in vitro.