SHAPE AND ORIENTATION OF OSTEOBLAST-LIKE CELLS (SAOS-2) ARE INFLUENCED BY COLLAGEN-FIBERS IN XENOGENIC BONE-BIOMATERIAL

The surface topography of a substratum has been shown to influence the growth and morphology of cells in culture. In this study, human osteo blast-like cells (Saos-2) were cultured on two types of xenogenic biom aterials obtained from bovine bone. Both biomaterials were similar in architectural organization and surface topography, but they differed i n matrix components. The first one was characterized by preservation o f the mineralized collagen matrix, and the second by complete deprotei nization which only preserved the mineral phase. Cells cultured at the surface of both biomaterials were observed using scanning electron mi croscopy. The beta(1)-integrin subunit, known to bind cell and collage n, is the major integrin of the osteoblast. It was localized using imm unogold in transmission electron microscopy. At the surface of the col lagen-containing matrix, cells exhibited an elongated shape and orient ed axis parallel to the underlying collagen bundles. The beta(1)-integ rin subunit was localized at the outer surface of cells, in close asso ciation with collagen and at the contact points between cells and biom aterials. In contrast, at the surface of the single mineral matrix, ce lls were round shaped with random disposition. Gold particles were fou nd around the cells with no specific relation to the biomaterial. Thes e results strongly suggest that the chemical nature of the surface of a bone biomaterial directly influences adhesion process, shape, and sp atial organization of cultured osteoblastic cells. (C) 1998 John Wiley & Sons, Inc.