title: Excess fibrinogen adsorption to monolayers of mixed lipids.
abstract: Adsorption of fibrinogen to the monolayers of mixed lipids, dipalmitoyl phosphatidyl choline (DPPC) and eicosylamine (EA) was measured at a surface pressure of 20 mN/m by an in situ surface plasmon resonance technique. Pressure-area isotherms of DPPC+EA mixtures on water and buffer subphases indicated good lipid miscibility and some contraction of the monolayers at intermediate and higher surface pressures. Surface electric potential of the DPPC+EA monolayers showed excess values for intermediate DPPC:EA ratios. Fibrinogen adsorption and its adsorption rates from a dilute solution (0.03 mg/ml) were proportional to the fraction of EA in the monolayer indicating that protein binding was primarily driven by electrostatic interactions between positive EA charges in the monolayer and a net negative protein charge. At a higher protein concentration (0.06 mg/ml) both the fibrinogen adsorbed amount and its maximum adsorption rate showed excess values relative to the pure EA for 1:1, 2:1 and 3:1 DPPC+EA monolayers. This excess adsorption could be explained, in part, by the contraction of the monolayers with intermediate DPPC:EA ratios which resulted in an excess surface electric potential.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, United States.
authors.forename: V
authors.initials: V
authors.lastname: Deshmukh
authors.forename: D W
authors.initials: DW
authors.lastname: Britt
authors.forename: V
authors.initials: V
authors.lastname: Hlady
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000327:Adsorption; D005340:Fibrinogen / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D010316:Particle Size; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D008055:Lipids; D008567:Membranes, Artificial; D015060:1,2-Dipalmitoylphosphatidylcholine; D005340:Fibrinogen