| AVS 54th International Symposium | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterials Interfaces Poster Session |
| Presenter: | S. Sarkar, University of Nebraska, Lincoln |
| Authors: | S. Sarkar, University of Nebraska, Lincoln L. Castro, University of Nebraska, Lincoln D.W. Thompson, University of Nebraska, Lincoln A. Subramanian, University of Nebraska, Lincoln J.A. Woollam, University of Nebraska, Lincoln |
| Correspondent: | Click to Email |
Protein adsorption onto surfaces continues to be widely researched, as it is an everyday occurrence either improving or impeding the quality of life. Often investigated are kinetics of adsorption. In the present work we monitored protein adsorption to surfaces with different chemistries. Modified chitosan surfaces and silicon wafers were used. Spin-cast Chitosan was cross-linked and activated with diepoxides and selected chemical ligands (n-butyl amine, t-butyl amine, n-octyl amine, 2,4,6 Tris and 2-t-Ethyl(butyl amine)) and anti-human albumin molecule. These surfaces were created to preferentially adhere to human serum albumin (HSA). Protein solutions consisting of HSA, immunoglobulin and fibrinogen dissolved in phosphate buffered saline were used to study adsorption processes. Solutions were introduced onto modified chitosan using a fluid cell, and dynamic data optically modeled to obtain protein adsorption profiles. Chitosan is a well known hydro-gel, and spun cast chitosan is anisotropic. Our EMA-based optical model accounts for this anisotropy. A thermodynamic adsorption model was formulated which accounts for changes in protein surface binding capacity during dynamic conformational changes. The model assumes irreversible binding of proteins and a process that is not diffusion limited. The adsorption profiles were then modeled and the parameters compared. Our studies indicate typical protein adsorption processes differ from a simplistic Langmuir model. It also describes changes in protein binding rates during a given adsorption cycle. We propose these regions of data result from surface bound protein conformation changes.