Human osteoblast adhesion on titanium alloy, stainless steel, glass and plastic substrates with same surface topography

Osteoblast adhesion on materials will depend on the surface aspects of materials which may be described according to their surface chemistry, surface topography or surface energy. To separate the effects of roughness and composition of materials on osteoblast response, we chose to compare substrates with various surface composition but with the same smooth surface. Ti6Al4V alloy, stainless steel, glass and standard tissue culture polystyrene were tested. Adhesion was evaluated using specific antibodies against adhesion proteins and by a quantitative cell detachment assay. After 1, 7 and 14 days, cells expressed extracellularly fibronectin fibers, and intracellularly type I collagen and osteopontin. Vinculin-labeled focal contacts were visible on all materials but were more frequent on glass and stainless steel surfaces. β1-integrin subunit-labeled patches were visible on all surfaces at each delay. The quantitative cell detachment assay showed few differences between materials. Adhesion was higher on metallic substrates although cell proliferation was higher on glass and stainless steel compared to tissue culture polystyrene and Ti6Al4V alloy. Substrates with various surface composition but with the same surface topography did not induce significant differences of adhesion although cell proliferation was variable.