Surface engineering strategies for control of protein and cell interactions

Surface engineering is an important tool in understanding the molecular mechanism of protein adsorption and cell-surface interactions with the aim of rational design of surfaces for different biological applications. This article first briefly summarizes some of the commonly used approaches to control biological interactions at the solid–water interface. Next, two different approaches are presented from the authors’ research to engineer surfaces that address some of the problems and limitations of current approaches to modulate protein adsorption at surfaces. The first, “static” strategy involves modifying a surface with an amphiphilic comb polymer that presents short oligoethylene glycol side-chains. Two different fabrication methods to synthesize these non-fouling coatings are described including spin-coating and surface-initiated polymerization. The second, “active” strategy to control protein adsorption involves grafting a stimuli-responsive biopolymer, derived from an oligomeric sequence found in mammalian elastin to a surface. This polypeptide exhibits a lower critical solution temperature (LCST) transition in aqueous solution. Surfaces grafted with these polypeptides exhibit a hydrophilic-hydrophobic transition in response to increased temperature or salt concentration. The change in the interfacial properties can be exploited to create “active” polymer grafts that enable reversible, triggered binding of proteins onto surfaces in response to an external stimulus.