Volumetric Interpretation of Protein Adsorption
Open Access
- Author:
- Noh, Hyeran
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 20, 2007
- Committee Members:
- Erwin A Vogler, Committee Chair/Co-Chair
David Lawrence Allara, Committee Member
Ralph H Colby, Committee Member
Christopher Alan Siedlecki, Committee Member - Keywords:
- Biomaterial
Surface Chemistry
Competitive Adsorption
Protein
Biocompatibility - Abstract:
- Mass-balance equations for the depletion method of measuring protein adsorption to hydrophobic, hydrophilic, and ion exchange surfaces are derived from a theory predicated on the idea that adsorbent capacity is limited by the extent to which the surface region can be dehydrated by displacement of interfacial water with protein. Adsorption from single-protein solutions and competitive adsorption from multi-component solutions are considered. Resulting mass balance equations are found to both anticipate and accommodate adsorption of human serum albumin (HSA), prothrombin (FII), immunoglobulin G (IgG), fibrinogen (Fib), and mixtures. Simultaneous and sequential competitive-protein-adsorption experiments demonstrate that proteins are not irreversibly adsorbed under the experimental conditions employed. Partition coefficients and thickness of adsorbed protein layers from depletion measurements corroborate estimates made from the interfacial energetics of protein adsorption and hydrophobic-interaction chromatography. Results demonstrate that proteins studied are weak biosurfactants with partition coefficients and commensurate free energy of adsorption . Agreement between theory and experiment suggests that protein adsorption to surfaces is reversibly controlled by what amounts to be the hydrophobic effect and that a set of quasi-thermodynamic rules dictate the essential physical chemistry of protein adsorption.