ATTACHMENT KINETICS, PROLIFERATION RATES AND VINCULIN ASSEMBLY OF BOVINE OSTEOBLASTS CULTURED ON DIFFERENT PRE-COATED ARTIFICIAL SUBSTRATES

Primary bovine osteoblasts were used to study in-vitro effects of atta chment on vinculin assembly in cells cultured on various artificial su bstrates. Materials coated with fibronectin and bovine serum albumin ( BSA) as well as untreated materials (tissue culture polystyrene and Ac lar foils) were chosen to investigate substrate-dependent proliferatio n du ri ng the fi rst 3 days of culture. Proliferation was highest on fibronectin-coated substrates, followed by BSA-coated and untreated su bstrates. During the first 24 h of cultivation, cell attachment kineti cs revealed no significant difference between the various substrates. After 24 h detach ment rates obtained by calcium depletion with ethyle nediaminetetraacetic acid were highest on uncoated materials, followed by BSA- and fibronectin-coated substrates. Phase contrast microscopy revealed typical osteoblast morphology after cell adhesion for 24 h. T he dynamic attachment process was concomitant with the reassembly of v inculin into streak-like focal contacts clustered on the ventral side of cells. The kinetics of vinculin reassembly were independent of the underlying coating. Thus, fibronectin coating of artificial substrates increased the attachment strength and proliferation rate of osteoblas ts. While the reassembly of vinculin in focal contacts seems to be a p rerequisite of osteoblast attachment in vitro, it does not seem to hav e profound effects on the subsequent cell behaviour on artificial subs trates.