Surface mobility of 2-methacryloyloxyethyl phosphorylcholine-co-lauryl methacrylate polymers

To design new polymers for use in vivo it is necessary to characterize the surface of the material to understand the interactions that occur when it is exposed to biological environments. Incorporation of phosphorylcholine (PC) into polymers has been shown to improve biocompatibility by suppressing unfavorable responses which occur on contact with body fluids. Here, a series of copolymers with varying ratios of the monomers 2-methacryloyloxyethyl phosphorylcholine (MPC) and lauryl (dodecyl)methacrylate (LMA) have been synthesized. The composition of the copolymers were analyzed using nuclear magnetic resonance spectroscopy (NMR), and coatings of these materials characterized using angle-resolved X-ray photoelectron spectroscopy (ARXPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The interaction of the copolymer coatings with protein was investigated using surface plasmon resonance (SPR), while dynamic contact angle (DCA) was used to monitor the surface hydrophobicity of the copolymers. The combination of the analytical techniques applied to the study of these copolymers has shown that the surfaces are extremely mobile and are able to rearrange depending on the environment in which the polymer is placed. SPR analysis has shown that the plasma protein fibrinogen, known to initiate the clotting cascade, does not adsorb to the surface of the copolymers once they are hydrated.