BEHAVIOR OF BONE-MARROW CELLS CULTURED ON 3 DIFFERENT COATINGS OF GEL-DERIVED BIOACTIVE GLASS-CERAMICS AT EARLY STAGES OF CELL-DIFFERENTIATION

Previous studies have shown different macrophage responses to three co mpact pellets (with slightly different chemical composition) of gel-de rived bioactive glass-ceramics of the CaO-P2O5-SiO2 system. In the pre sent study primary bone marrow cells directed in vitro to form osteobl astic or osteoclastic cells were cultivated on glass slides coated by these three glass-ceramics. Glass slides were used as controls. In ost eoblastic cultures alkaline phosphatase activity varied, depending on the type of coatings. Northern analysis showed high mRNA expressions o f bone-related proteins on both the glass-ceramics and control glass. Mineralized nodules were not formed on the control glass, but coating glass slides with the glass-ceramics promoted mineralization without a ny substantial differences between the types of coatings. In osteoclas tic cultures, the normal morphology of tartrate resistant acid phospha tase-positive multinucleated cells on standard culture plates was alte red on the control glass and the glass-ceramics. The number of these c ells differed, depending on the type of coatings, with no particular d ifferences in the arrangement of F-actin by these cells. These analyse s demonstrate complete biocompatibility of the glass-ceramic coatings but not the control glass, on which the cells failed to form mineraliz ed nodules. The phenotype expression of the cells appeared to be influ enced by microstructure, surface roughness, and the general character of the coatings rather than their surface reactivity. (C) 1998 John Wi ley & Sons, Inc.