Interfacial rheology of blood proteins adsorbed to the aqueous-buffer/air interface

Integrative Biosciences Graduate Program, Huck Institutes for Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
Biomaterials (Impact Factor: 8.31). 07/2006; 27(18):3404-12. DOI: 10.1016/j.biomaterials.2006.02.005
Source: PubMed

ABSTRACT Concentration-dependent, interfacial-shear rheology and interfacial tension of albumin, IgG, fibrinogen, and IgM adsorbed to the aqueous-buffer/air surface is interpreted in terms of a single viscoelastic layer for albumin but multi-layers for the larger proteins. Two-dimensional (2D) storage and loss moduli G(') and G(''), respectively, rise and fall as a function of bulk-solution concentration, signaling formation of a network of interacting protein molecules at the surface with viscoelastic properties. Over the same concentration range, interfacial spreading pressure Pi(LV) identical with gamma(lv)(o)-gamma(lv) rises to a sustained maximum Pi(LV)(max). Mixing as little as 25 w/v% albumin into IgG at fixed total protein concentration substantially reduces peak G('), strongly suggesting that albumin acts as rheological modifier by intercalating with adsorbed IgG molecules. By contrast to purified-protein solutions, serially diluted human blood serum shows no resolvable concentration-dependent G(')and G('').

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