Conformation of human plasma proteins at polymer surfaces: the effectiveness of surface heparinization.

Studies were made on the adsorption of two human plasma proteins, albumin (HSA) and fibrinogen (HFg), onto three different polymeric surfaces: commercial pellethane 2363-80AE (PU); pellethane crosslinked with a poly(amido-amine) (PUPA); and heparinized PUPA, using in situ ATR/FTIR spectroscopy (attenuated total reflection Fourier transform infrared spectroscopy). Conformational changes were found to occur on the two proteins upon adsorption onto bare PU and PUPA, and the protein unfolding on bare PU was also found to be time dependent. On the contrary, the two proteins do not change conformation when they are adsorbed onto the heparinized surface, emphasising the effectiveness of surface heparinization.