Blood compatibility of poly(2-methoxyethyl acrylate) - Design novel biointerfaces

The Poly(2-methoxyethyl acrylate) (PMEA) surface shows excellent blood compatibility with respect to the coagulation, complement, and platelet systems when compared with other polymer surfaces. To clarify the reasons for this good compatibility, kinetics of protein adsorption and desorption on PMEA surface, and the structure of water in the hydrated PMEA were investigated. Poly(2-hydroxyethyl methacrylate) (PHEMA) and polyacrylate analogs were used as references. The amount of protein adsorbed onto PMEA was very small, and close to that adsorbed onto PHEMA. PMEA showed the low denaturation and the high dissociation rate constant of the proteins adsorbed onto PMEA. The hydrated water in PMEA could be classified into three types; free water, freezing-bound water, and non-freezing water. Cold crystallization of water in the heating process was clearly observed at -42 °C. This cold crystallization is interpreted as the phase transition from the amorphous ice to the crystal ice that belongs to the freezing-bound water in PMEA. We hypothesized that the freezing-bound water layer between free water and non-freezing water was an important factor for the excellent blood compatibility of PMEA. The present study also describes the fabrication and characterization of highly regular porous polymer films formed by a simple casting technique. The porous film with controlled pore size from 0.2 to 100 μm is used for tissue engineering scaffolds and biomedical devices.