Detection of specific plasma proteins on surfaces by immunospecific adhesion of dyed polystyrene beads

This paper describes and evaluates a method for quantifying the amounts of specific plasma proteins adsorbed to biomaterial surfaces. In particular, it demonstrates that macroscopic images ('stains'), that assess the spatial distribution of albumin, IgG, fibrinogen, and HMK (high molecular weight kininogen), can be obtained over areas of at least 12 cm2 using immunospecific adhesion of dyed polystyrene beads. Stain intensities, measured with a scanner and an image analysis system, were found to quantify the amount of specific protein in the solution used to coat the surfaces. Results obtained with the proposed method produced single protein isotherms for albumin, immunoglobulin G (IgG) and fibrinogen that followed Langmuir-like adsorption behavior and were similar to previously published isotherms. The HMK isotherm also exhibited Langmuir-like adsorption behavior. The proposed method also detected the presence of an expected maximum in the adsorption of fibrinogen onto glass as a function of plasma dilution. Adsorption of fibrinogen out of 6.4% plasma onto glass from a separated flow produced results indicating the quantity as well as the location of fibrinogen at the boundary of the separated region. This result confirmed the utility of the proposed method for detecting spatial distributions of specific proteins adsorbed from plasma in practical devices.