2-DIMENSIONAL, SPATIAL ARRANGEMENT OF FIBRONECTIN ADSORBED TO BIOMATERIALS WITH DIFFERENT WETTABILITIES

The effects of concentration, pH and substratum wettability on the two dimensional, spatial arrangement of adsorbed fibronectin are determined. Substrata with different wettability were exposed to a well defined flow of a fibronectin solution (0.1 or 1 mg/ml) in potassium phosphate buffer (pH 7.0 or 4.8) during 120 minutes at a shear rate of 20 s-1. Rotary shadowed replicas of the surfaces were examined by transmission electron microscopy. Well defined structures, island-like in character on the low wettability substrata and knotted, reticulated on the high wettability substrata, could be seen in case of adsorption from pH 7.0 and the high concentration solution. Structures became more blurred upon lowering the solution pH and fibronectin concentration. Compared with bovine serum albumin, fibronectin shows smaller island-like structures, but the reticulated structure is thicker than for albumin.