Human serum albumin as a probe for surface conditioning--a study of the ageing effect.

I125 radiolabelled HSA (HSA-I125) was utilised as a probe to quantify protein adsorption onto polystyrene (PS) and Poloxamine 908 coated PS (PS-908) particles. Upon ageing of the HSA-I125 a dramatic increase in the amount of protein adsorbed onto the two particle systems was observed. This phenomenon was not due to lability of the protein-radionuclide bond and no modifications in the secondary structure of the native and radiolabelled protein could be identified which could explain this unusual ageing effect. Using the amount of protein adsorbed to the uncoated particles as a control for each time point, it was possible to reproducibily determine the amount of HSA adsorbed to the coated particles.