SI-CA-P XEROGELS AND BONE MORPHOGENETIC PROTEIN ACT SYNERGISTICALLY ON RAT STROMAL MARROW CELL-DIFFERENTIATION IN-VITRO

This study describes a novel bioactive xerogel glass as a carrier for bone morphogenetic protein (BMP) and the value of this carrier in term s of stimulating osteogenic activity of rat stromal marrow cells in vi tro. These cells were seeded onto the surface of xerogel glass disks w ith BMP either incorporated in the glass, adsorbed to the surface of t he glass, or added to the culture media and then compared to cells on glass with no added BMP or to cells on tissue culture plastic (TCP) wi th and without BMP. Cells were cultured for 6 and 10 days and examined for total DNA, alkaline phosphatase activity, and osteocalcin and tot al protein production. Stromal cell differentiation, as measured by al kaline phosphatase activity and osteocalcin synthesis was most increas ed when the BMP was incorporated or adsorbed onto the xerogel glass. C ells on xerogel glass without BMP were more differentiated than cells grown on plastic with BMP, thereby demonstrating the additive effect o f a bioactive substrate and BMP on osteoblastic cell differentiation. These data indicate that xerogel glass effects differentiation of cell s with osteogenic potential and that it can serve as a delivery vehicl e for BMP. (C) 1998 John Wiley & Sons, Inc.