【摘要】 用三氯化铝催化六氯三聚膦腈开环聚合制得线性聚二氯膦腈(PDCP),通过PDCP磷原子上的亲核取代反应,合成了新的水溶性高分子聚[(甲氧基乙氧基乙氧基)1.0(乙氧基吡咯烷酮)1.0]膦腈(P3),用31P NMR,1HNMR,13C NMR和IR对其结构进行了确证,用DSC测定了其玻璃化转变温度Tg和熔融温度Tm,用蒸汽压渗透法(VPO)测定了其数均分子量.改进了聚二(乙氧基吡咯烷酮)膦腈(P2)的合成方法.体外降解实验表明,P3具有和P2类似的pH响应性降解行为,降解速率在pH=5.0时最快,而在pH=7.4和8.0时较慢.P3在所测试的3个pH缓冲溶液中均比P2降解慢.用31P NMR、薄层色谱(TLC)和滴定法对降解产物进行了检测,初步推断了P3在不同pH介质中的水解机理,其在pH=5.0的缓冲溶液中的降解,除侧链断裂外,聚膦腈的骨架也裂解;而在pH=7.4和8.0时的降解仅为侧链的断裂.用噻唑蓝(MTT)比色法进行的体外细胞毒性评价实验表明,P3及其在pH=5.0的缓冲溶液中降解49 d后的产物均对细胞表现出了很好的生物相容性,而且其降解产物在浓度为800μg/mL时还表现出一定的促进细胞增殖作用.更多还原

【Abstract】 Polydichlophosphazene(PDCP) was prepared by the ring-opening polymerization of hexachlorocyclotriphosphazene in the presence of 2%AlCl3.A new mixed substituent poly(organophosphazene) bearing 2-(2-oxy-1-pyrrolidiny) ethoxy and methoxyethoxyethoxy side groups was synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene) with the sodium salt of 1-(2-hydroxyethyl)-2-pyrrolidone and sodium methoxyethoxyethoxide.Its structure was verified by 31P NMR,1H NMR,13C NMR,IR and DSC.Its molecular weight was determined by vapor pressure osmometry(VPO).18-Crown-6 was used in the synthesis of poly[di(2-oxy-1-pyrrolidiny)ethoxyphophazene](PYRP) as phase transfer catalysis in order to improve its synthetic method.The new polymer and PYRP were water-soluble and their ]in vitro] degradation behavior was studied at varied pH conditions.The results indicate that the degradation of poly(organophosphazenes) with(2-oxy-1-pyrrolidiny)ethoxy side groups is dependent on pH of the buffer solution.The rate of hydrolysis was more rapid at pH=5.0 than at pH=7.4 and pH=8.0.It was shown that addition of methoxyethoxyethoxy side group to PYRP structure resulted in a decrease in the rate of hydrolysis.The hydrolysis products of the poly(organophosphazenes) were analyzed by 31P NMR,thin layer chromatography(TLC) and titration methods.A hydrolysis pathway of the new polymer in buffer solutions with pH=5.0,7.4 and 8.0 was proposed.The degradation of the polymers at pH=5.0 involved a hydrolytic cleavage of(2-oxy-1-pyrrolidiny)ethoxy from the chain followed by the degradation of the phosphorus-nitrogen backbone to form phosphate and ammonium.However,the degradation of the polymers at pH=7.4 and pH=8.0 was only cleavage of the side group.The MTT test for the new polymer and its hydrolysis products at pH=5.0 in HepG2 cell revealed that an increase in polymer concentration from 1.3 to 800 μg/mL was not harmful for the cell survival.The hydrolysis products of the new polymer at 800 μg/mL were able to promote cell proliferation.更多还原