The adsorption state of liposomes on a polymer surface conmerizable group was effective in stabilizing liposomal structaining a phosphorylcholine group, that is, v-methacryloyloxyalture (3-7). Bonte and co-workers investigated the polymerkyl phosphorylcholine (MAPC) polymer, was evaluated using a ization of phospholipids with a polymerizable group and quartz crystal microbalance and an atomic force microscope. After revealed that the polymerized liposomes did not induce aga quartz crystal resonator coated with the MAPC polymer or gregation of platelets in either plasma or blood (5). Adsorppoly[2-hydroxyethyl methacrylate (HEMA)] was equilibrated tion of liposomes on the polymer support is a good method with distilled water, the quartz crystal was contacted with a dipalfor creating a biomembrane-like surface. Kano et al. reported mitoylphosphatidylcholine (DPPC) liposomal suspension. The that polyamide microcapsules treated with phosphatidylchoresonance frequency change during liposome adsorption on the poly(HEMA)-coated resonator was larger than that on the MAPC lines suppressed platelet adhesion (8). Hall and co-workers polymer-coated resonator. The temperature response based on the carried out a thromboelastographic study of various surfaces phase transition of adsorbed DPPC liposomes, that is, the liquid treated with phospholipids and observed the elongation of crystalline state to gel state, on the MAPC polymer-coated resonaclotting time compared with the nontreated surface (9). tor was more sensitive than that on the poly(HEMA)-coated reso-These results indicated that an organized phospholipid surnator. Moreover, when the DPPC liposomes adsorbed on the polyface having self-assembled biomimetic membranes could mer surfaces were disintegrated with a nonionic surfactant, it took suppress biological responses. longer for the frequency to return to the initial value of the poly-We have synthesized various phospholipid polymers con-(HEMA)-coated resonator than to that of the MAPC polymertaining 2-methacryloyloxyethyl phosphorylcholine (MPC) coated resonator. According to atomic force microscopic observamoieties as novel hemocompatible and biocompatible matetion of the polymer surface after treatment with the liposomal suspension, the DPPC liposomes adsorbed on the MAPC polymers rials (10-16). The MPC polymers completely inhibited maintained their spherical shape well. We conclude that DPPC platelet adhesion, even when the MPC polymer came in liposomes adsorbed on the poly(HEMA) surface can penetrate a contact with human whole blood without anticoagulant (15). hydrated layer and its ordered structure. On the other hand, DPPC Moreover, plasma proteins barely adsorbed to the MPC polyliposomes may adsorb to the MAPC polymer surface without mer surface . This evidence suggested that MPC change in their original structure.