Tetrafluoroethylene (
TFE) glow discharge-treated
Dacron vascular grafts resist
thrombus deposition, embolization and thrombotic occlusion. In addition,
albumin adsorbed on
TFE-treated surfaces resists elution by
sodium dodecyl sulfate (SDS). Since the tight binding of
albumin to
TFE-treated surfaces may contribute to their thromboresistant character, we decided to examine the mechanism responsible for this tenacious adsorption. We have investigated
albumin adsorption and retention (after SDS elution) on a number of untreated and glow discharge-treated surfaces.
Fluorocarbon glow discharge-treated
polymers retain a larger fraction of the adsorbed
albumin than
ethylene and
hexamethyldisiloxane glow discharge-treated surfaces.
Albumin retention by surfaces appears to be closely related to their surface free energy (in air). Low energy surfaces (in air), whether untreated or glow discharge-treated, retain a larger fraction of the
albumin adsorbed than higher energy surfaces. The lowest energy surfaces should have the highest interfacial energies in water, with correspondingly high driving forces for adsorption of
proteins. This can lead to the formation of multiple binding sites upon adsorption, permitting strong hydrophobic interactions, which leads to the observed strong binding.