The kinetics of protein adsorption on synthetics and modified natural surfaces

• Published in: Journal of colloid and interface science 1982-01, Vol.86 (2), p.539-558
• Main Authors: Bornzin, Gene A, Miller, Irving F
• Format: Article
• Language: English
• Subjects: albumin; fibrinogen
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/0021-9797(82)90098-4

The kinetics of adsorption of albumin and fibrinogen from phosphate buffered saline (pH 7.35, 280 mosmol) was studied as a function of time, temperature, and bulk protein concentration on Cuprophan (regenerated cellulose), Silastic (silicone rubber), and Shiley heart valve xenografts under static conditions. Adsorption of both proteins on the synthetics appeared to be rapid, irreversible with respect to dilution, and at surface concentrations not exceeding what would be expected for a monolayer. A diffusion-limited model, using the Smoluchowski boundary condition, was derived and was shown to demonstrate the essential characteristics of sorption on synthetics. Both proteins adsorbed to the xenograft with a reversibly bound protein fraction and an irreversibly bound fraction. The reversible fraction was modeled well by a second-order kinetic (Langmuir) process far from saturation. Energies of activation were estimated to be about 3 and 6 kcal/mole for fibrinogen and albumin, respectively. Enthalpies of adsorption were very low, 0.4 kcal/mole for fibrinogen and 1.5 for albumin. The irreversibly bound fraction was modeled well as a diffusion-limited process far from saturation.