COLL 184 |
| Min Sze Wang and Anneta Razatos. Department of Chemical and Materials Engineering, Arizona State University, P.O. Box 876006, Tempe, AZ 85287-6006 |
| Failure of implanted biomaterials is commonly due to non-specific protein adsorption, which in turn causes adverse reactions such as the formation of fibrous capsules, blood clots or bacterial biofilm infections [1]. Current research efforts have focused on modifying the biomaterial interface to control protein reactions. Designing biomaterial interfaces at the molecular level, however, requires an experimental technique that provides detailed, dynamic information on the forces involved in protein adhesion. The goal of this study was to develop an atomic force microscope (AFM)-based technique to evaluate protein adhesion on biomaterial. In this study, the AFM was used to evaluate i) protein-protein, ii) protein- substrate, and iii) protein-dextran interactions. Specifically, the AFM was used to measure the pull-off forces between BSA-tips/BSA-surfaces and BSA-tips/anti-BSA-surfaces. Results from these protein-protein studies were consistent with the literature. More importantly, the successful measurement of antibody-antigen binding interactions demonstrates that both the BSA and anti-BSA proteins retain their folded conformation and remain functional following our immobilization protocol. The AFM was also used to quantify the physiochemical interactions of proteins during adhesion to various self assembled monolayers (SAMs) and dextran-coated substrates representative of potential biomaterial interface modifications. Dextran, which renders surfaces very hydrophilic, was the only surface coating that BSA protein did not adhere to. Hydrophobic interactions were not found to play a significant role in BSA adhesion. Therefore, the dextran molecules may resist protein adhesion by repulsive steric effects or hydration pressure. In summary, the AFM-based methodology provides dynamic, quantitative data about protein adhesion at the nano-scale. 1. Caster DG, Ratner BD. Biomedical surface science: Foundatoins to fornteirs. Surface Science 2002;500:28-60. |
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Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, March 29, 2004 Disneyland -- North Exhibit Hall, Poster
Division of Colloid and Surface Chemistry |