Relationship between the water structure in the vicinity of carboxybetaine polymers and their biocompatibility

Structure of water in the vicinity of carboxybetaine(CMB), n-buthyl methacrylate(BMA) polymers and their copolymers with various compositions was investigated by using vibrational spectroscopies. Raman spectroscopy has revealed that, in contrast with ordinary polyelectrolytes, the zwitterionic polymers, PCMB and water-soluble P(BMA/CMB), did not affect the hydrogen-bonded network structure of water in their aqueous solutions. ATR-IR spectra of water sorbed into the P(BMA/CMB) films was similar to that of free water, but that in PBMA film was not. On the other hand, number of platelets adhered to the P(BMA/CMB) films was much smaller than that of PBMA film. These results suggest that the water structure is very important factor to generate biocompatibility of polymers.