【摘要】 将疏水性不同的共聚物混合制备可注射水凝胶。通过先核后臂法分别制备出线型聚乳酸-聚乙二醇（PLLAPEG）共聚物和星型聚乳酸-聚乙二醇单甲醚（PLLA-mPEG）共聚物,将两者水溶液进行混合,采用试管翻转法测定混合溶液热致相转变行为。结果表明:线型PLLA-PEG₆₀₀溶液相转变范围15—42℃,星型PLLA-mPEG750溶液相转变范围52—68℃,当星型PLLA-mPEG750溶液与线型PLLA-PEG₆₀₀溶液混合,形成了以疏水性较强的线型共聚物为核,疏水性较差的星型共聚物为壳的核壳结构复合物,其相转变温度介于2种共聚物相转变温度之间,可作为注射水凝胶。体外药物释放结果表明:复合水凝胶对所包载的盐酸乌拉地尔具有良好的缓释作用,动力学释放符合一级动力学方程。更多还原

【Abstract】 The injectable hydrogels were prepared by mixing the copolymers with different hydrophobicity. The linear PLLA-PEG copolymers and star-shaped PLLA-mPEG copolymers were synthesized by the " core first" method respectively. The solution of linear PLLA-PEG copolymer mixed with the solution of star-shaped PLLA-mPEG copolymer,and then the sol-gel transition temperatures of the composite solutions were determined with the test tube inverting method. The sol-gel transition temperatures of the composite hydrogels showed remarkable changes. The sol-gel transition temperatures were from 15 to 42 ℃ for the solution of linear PLLA-PEG copolymers,and from 52 to 68 ℃ for the solution of star-shaped PLLA-mPEG copolymers. The sol-gel transition temperatures were between star-shaped PLLA-mPEG and linear PLLA-PEG when star-shaped PLLA-mPEG copolymers were mixed with linear PLLA-PEG copolymers. The thermo-responsive composite hydrogels could be used as injectable hydrogel. The release study indicated that the composite hydrogels exhibited better sustained-release capacity,and in vitro release kinetics were described by the first order equation.更多还原