Random Copolymer Films with Molecular-Scale Compositional Heterogeneities that Interfere with Protein Adsorption

Smooth surfaces with compositional heterogeneities at a molecular-length scale are presented with the goal of disrupting surface-protein interactions. These surfaces are synthesized by utilizing photoinitiated chemical vapor deposition (piCVD) to deposit thin films of random copolymer consisting of highly hydrophilic and highly hydrophobic comonomers. Swellability, wettability, and surface roughness could be systematically controlled by tuning the copolymer composition. The surface composition was dynamic, and the surface reconstructed based on the hydration state of the film. Proteins adsorbed to the copolymer films less readily than to either of the respective homopolymers, indicating a synergistic effect resulting from the random copolymer presenting molecular-scale compositional heterogeneity. These results provide direct evidence that protein adsorption can be disrupted by such surfaces and a simple analytical model suggests that the heterogeneities occur over areas encompassing 4-5 repeat units of the polymer. The synthetic method used to create these films can be used to coat arbitrary geometries, enabling practical utility in a number of applications.