Al2O3 doped apatite-wollastonite containing glass ceramic provokes osteogenic differentiation of marrow stromal stem cells

Abstract

Fresh marrow cells were obtained from femora of Fischer rats and cultured in a medium containing 15% fetal calf serum (FCS) until confluence. After trypsinization, cells were subcultured at a cell density of 100 × 10³/35‐mm well in the presence of FCS, β‐glycerophosphate, and ascorbic acid phosphate on four different culture substrata. The period of subculture was 2 weeks; the substrata used were the culture dish, apatite‐wollastonite containing glass ceramic (AW), hydroxyapatite coated AW (HA/AW), and Al₂O₃ doped AW (Al/AW). The HA coating was attained by the incubation of AW in simulated physiological solution. The glass matrix of AW and HA/AW contained MgO, CaO, P₂O₅, and SiO₂; Al/AW contained Al₂O₃ in addition to these components. The subculture on Al/AW substratum showed many alkaline phosphatase (ALP) positive nodules and the highest ALP activity. On a Northern blot analysis the housekeeping gene of β‐actin mRNA was evenly detected from the cells cultured on all substrata; however, bone‐specific osteocalcin mRNA was only detected from the cells on Al/AW. These results indicate that Al/AW provokes the osteoblastic differentiation of marrow stromal stem cells. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 44, 381–388, 1999.