Behavior of Blend Polymers Composed of Phospholipid Polymer and Poly (vinyl alcohol) in Aqueous Solution
Yoichi Shindo, Kenta Nakagawa, Kikuko fukumoto, Ikki Meguro
Department of Chemistry, Faculty of Science, Toho University
Japan

Keywords: Phospholipid Polymer , Poly (vinyl alcohol), electrolytes

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Phospholipids are the main components of the biomembrane and interesting
substances in biological and biomedical field. A methacrylate copolymers
having the phospholipid polar group, 2-methacryloyloxyethyl
phosphorylcholine (MPC) show excellent blood compatibility. The protein
adsorption-resistant properties of MPC copolymers have been observed.
In this work the behaviors of blend polymer chains in aqueous solutions were
estimated by fluorescence and viscosity measurements. In addition, the
behaviors of the polymer chain were measured in aqueous solutions of various
electrolytes: NaCl, KCl and Na2SO4, and the effects of the added
electrolytes on the dimension of polymer chains were examined. The blended
polymer solutions were prepared from 2-methacryloyloxyethyl
phosphorylcholine and 2-hydroxyethyl methacrylate (HEMA), poly (MPC-co-HEMA)
or n-butyl methyl methacrylate (BMA), poly(MPC-co-BMA) with different PVA
compositions. The intensity of a fluorescence probe, sodium
8-anilino-naphthalene sulfanate (ANS-Na), increased with increasing MPC
component in a poly (MPC-co-HEMA). And it increased more rapidly than
90%MPC. The increase in fluorescence intensity is due to the strong
hydrophobic interaction around the polymer chain. On the other hand, the
viscosity of polymer solutions decreased. The conformation of polymer coils
is appreciably affected by the presence of HEMA in a poly (MPC-co-HEMA). In
spite of the proportion of HEMA component in the poly (MPC-co-HEMA), the
change in fluorescence intensity and viscosity of polymer solutions
increased slowly with increasing concentration of PVA in blend polymers.
The conformation of PMPC and poly(MPC-co-BMA) chains is scarcely influenced
by the presence of electrolytes in an aqueous solution. These results
suggest that the hydration state of water molecules on the MPC coil is quite
different from that of polymers such as poly(HEMA) and poly(vinyl alcohol).
The characteristics of the MPC polymer system are closely related to the
state of water molecules around the polymer chain. The conformation of
phospholipid polymers in aqueous solutions is little affected by the
addition of a PVA or electrolytes. The behavior of blend polymers composed
of poly (MPC-co-HEMA) with a photocrosslinkable PVA in aqueous solutions is also discussed.