(253be) Exploration of the Hierarchal Roles of Surface Features Facilitating the Adsorption of Biomolecules

Authors: 
Beckner, W., University of Washington
Pfaendtner, J., University of Washington
Recent development in the anti-fouling properties of Self-Assembled Monolayers (SAMs) has largely focused on increasing the enthalpic association of a hydration layer along the interface of such surfaces with water. This has lead to the creation of surfaces that go beyond hydrogen-bonding with surrounding water molecules to ionic solvation, i.e. zwitterionic surfaces. However, an entropic penalty due to chain restriction also disfavors biomolecule-surface adsorption. While there isn't an outright dichotomy between the entropic point of view in SAM anti-fouling behavior and the more recent development of zwitterionic materials, an overarching theory on the protein adsorption resistance for surfaces is lacking. To isolate the effect of this entropic penalty amid changing packing densities, we performed all-atom (AA) molecular dynamics (MD) simulations of explicitly solvated systems of lysozyme and seven monomer length oligo (ethylene glycol) (OEG) SAMs. The rate of protein adsorption as well as the conformation and orientation of the protein upon adsorption were examined. It was found that chain spacing was a strong determinant in adsorption properties while chain mobility played a secondary role. In addition we performed AA MD simulations of a sodium styrene sulfonate (NaSS) surface in the presence of water and protein and investigated the features of the NaSS surface that selectively desorb extracellular matrix (ECM) proteins. This poster will discuss the aspects of the styrene sulfonate monomer that facilitated adsorption and end with a short perspective on how these features could be further optimized to selectively adsorb ECM proteins.