Oxy- and deoxyhaemoglobin adsorption onto glass and polymer surfaces

The adsorption of deoxyhaemoglobin (deoxyHb) and oxyhaemoglobin (oxyHb) was determined on clean glass, n-pentyl triethoxysilane (NPS)-treated glass, polystyrene (PS), and a polyetherurethane (PEU). The adsorbed amounts range from 0.1 to 0.6 micrograms/cm2 for oxyHb and from 0.3 to 0.7 micrograms/cm2 for deoxyHb. DeoxyHb adsorbs onto all these surfaces more than oxyHb. The more hydrophobic the surface, the more adsorption of both deoxy and oxyHb forms. These results suggest the oxyHb and deoxyHb interact differently with the surfaces studied. It is likely that the surface hydrophobicity of Hb plays a major role in Hb adsorption onto surfaces; the deoxyHb surface is more hydrophobic than the oxyHb surface. The binding sites for Hb adsorption may include the clefts between alpha 1, beta 1. A surface-induced dimerization mechanism is proposed to explain the adsorption of oxyHb.