IN-VITRO INVESTIGATION OF NOVEL CALCIUM PHOSPHATES USING OSTEOGENIC CULTURES

A rat bone marrow stromal cell (RBM) culture was used to evaluate nove l bioactive calcium phosphate ceramics. Three rapidly resorbable, glas sy crystalline materials with the main crystalline phase Ca2KNa(PO4)(2 ) were investigated (sample code GB 1a, GB 14, GB 9). These materials were designed to exhibit a higher degree of biodegradability than tric alcium phosphate. Additionally, a bioactive glass ceramic of low biode gradability was examined (sample code AP 40). REM cells were cultured on the disc-shaped test substrata for 14 d. The culture medium was cha nged and calcium and phosphate concentrations of the medium were deter mined daily. Specimens were evaluated using light microscopy and morph ometry of the cell-covered substrate surface, scanning electron micros copy and energy dispersive X-ray analysis. Except for GB la, the rat b one marrow cells attached and grew on all substrate surfaces. Of the d ifferent calcium phosphate ceramics tested, AP 40 facilitated osteobla st growth and the elaboration of the extracellular matrix to the highe st degree followed by GB 9 and GB 14. The inhibition of cell growth en countered with GB la seemed to be related to its high phosphate ion re lease.