(776g) Learning about Ligand-Receptor Interactions, Pollymers and Biological Recognition through Surface Forces

Much experimental and theoretical effort has been directed at elucidating the forces and dynamics of breaking, rupturing or unbinding ligandâ??receptor bonds, e.g., measuring the bond strength as a function of pulling rate or time using a variety of techniques. In contrast, much less attention has been given to the formation of ligandâ??receptor bonds. Using a combination of theory (analytical and simulations) and direct experiments (using the Surface Forces Apparatus technique) of a polymer tethered ligand receptor system, the role of tether dynamics, ligandâ??receptor binding strength, tethered architecture, and grafting density in determining the spatial range, capture time, and subsequent adhesion of complementary surfaces will be explored. In addition, the impact of the tethering chains' nonspecific repulsive interactions with model membranes, adhesion under flow, and implications for targeting polymerâ??coated particles towards biomimetic surfaces and cells will be discussed. Methods for tailoring specific adhesion without altering the ligandâ??receptor bond strength will be highlighted.