Summary
The adsorption of various plasma proteins to three solid surfaces has been studied
as a function of plasma concentration. Albumin adsorption on glass showed no dependence
on plasma concentration and increased to a plateau value on both polyethylene and
siliconized glass. Immunoglobulin G (IgG) adsorption showed no dependence on plasma
concentration on any surface. Fibrinogen adsorption increased with plasma concentration
and then decreased, the maximum occurring at about 1% normal plasma concentration
and varying somewhat with the surface. On glass the kinetics of fibrinogen adsorption
was dependent on plasma concentration: at concentrations less than the adsorption
maximum, the kinetics was conventional, with adsorption increasing onto a plateau;
at concentrations greater than the adsorption maximum, kinetics curves also showed
maxima the position of which shifted to longer times as plasma concentration decreased.
These data are interpreted in terms of competitive adsorption between fibrinogen and
other, as yet unidentified species in plasma. The data reported are in general agreement
with the model of Vroman (12) for plasma-surface interactions which holds that initially
adsorbed fibrinogen is later replaced by high molecular weight kininogen (HMWK), the
rate of replacement depending on the relative activity of the surface in promoting
coagulation.
Keywords
Artificial surfaces - Fibrinogen - Protein adsorption - Blood compatibility - Plasma
dilution effects
