Preparation of dimethylsiloxane type of block copolymer * with nonthrombogenicity as biomedical materials

1.以乙二胺为扩链剂，在3-二(羟丙基)-四甲基二硅氧烷存在下，聚四氢呋喃与4，4‘-二苯基甲烷二异氰酸酯进行缩合反应，合成了主链含四甲基二硅氧烷(TMDS)部分的聚醚型氨基甲酸酯。结果表明：1.在空气中，TMDS部分位于PEUU-Si薄膜表面，PEUU-Si吸附了白蛋白。采用等离子体辐照-后聚合技术，制备了甲基丙烯酰氧基乙基磷胆碱(MPG)改性聚对苯二甲酸乙二酯(PMPC-g-PET)薄膜。PMPC-g-PET比原来的PET膜吸附更少的血清蛋白。卵磷脂吸附在PMPC-g-PET上，显示出抑制纤维蛋白形成的活性，对小鼠成纤维细胞(L-929)和血小板无粘附性。通过甲基丙烯酸甲酯与O-甲基丙烯酰基-L-丝氨酸或-L-脯氨酸的乳液共聚合，制备了L-丝氨酸和L-脯氨酸部分改性的聚甲基丙烯酸甲酯微球。位于颗粒表面的氨基酸部分。研究发现，蛋白质在颗粒上的吸附被有效地抑制。以聚二甲基硅氧烷型偶氮引发剂为引发剂，通过自由基聚合制备了一系列以PMPC、聚[甲基丙烯酸羟乙酯]、聚(2，3-二羟丙基甲基丙烯酸丙酯)和聚(L-甲基丙烯酰氧氧基二柠檬醇)为亲水链段的聚二甲基硅氧烷嵌段共聚物。在水中，亲水链段迁移到共聚物表面，抑制了对血清蛋白和血小板的吸附，比原来的聚二甲基硅氧烷少。含有PMPC链段的嵌段共聚物对L-929与血小板无粘附性。

1. Polyetherurethaneureas including tetramethyldisiloxane(TMDS) moiety in main chain were obtained frompolyaddition of polytetrahydrofuran to 4, 4'-diphenylmethane diisocyauate in the presence of 3-bis(hydroxypropyl)-tetramethyldisiloxane, using ethylenediamine as a chain extension reagent. It was found that the TMDS moiety was located on the surface of the PEUU-Si film in air and that PEUU-Si adsorbed albumin.2. Surface modified poly(ethylene terephthalate) (PET) films with the 2-(methacryloyloxy)ethyl phosphoryicholine(MPG), PMPC-g-PET, was prepared by plasma irradiation-post polymerization technique. PMPC-g-PET adsorbsless serum proteins than the original PET film. Lecithin adsorbed on PMPC-g-PET which showed activity for the inhibition of fibrin formation and no adhesion of mouse fibroblasts (L-929) and platelets.3. Poly(methyl methaciylate) microspheres modified with L-serine and L-proline moieties were prepared by emulsion copolymerization of methyl methacrylate with O-methacryloyl-L-serine or -L-proline. Amino acid moieties located on the surface of particles. It was found that the adsorption of proteins on particle was effectively suppressed.4. A series of polydimethylsiloxane block copolymers containing PMPC, poly[2-(hydroxyethyl) methacrylate], poly(2, 3-dihydroxypropyl methacrylate), and poly(l-methacryloyloxy dulcitol) as hydrophilic segments were prepared by radical polymerization of corresponding monomers initiated with polydimethylsiloxane type of azo-initiator. It was found in water that the hydrophilic segments migrated to the surface of copolymer which suppressed the adsorption of serum proteins as well as platelets, less than the original polydimethylsiloxane as control. The block copolymer containing PMPC segment showed no adhesion of L-929 and platelets.