The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measu...The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measured d n /d c of the solution decreases regularly and smoothly with increasing temperature until to the specific coil globule transition temperature of PNIPAM (around 32 ℃) and afterwards it increases with increasing temperature on the contrary. This extraordinary phenomenon is successfully explained and treated by a quantitative theory in terms of accompanying solvation desolvation process in the course of coil globule transition of the polymer chain in solution.展开更多
以卟啉衍生物为内核,采用可逆加成-断裂链转移(RAFT)聚合法合成了温度敏感性聚己内酯-聚N-异丙基丙烯酰胺。用FT-IR、1 H NMR、GPC、TEM、分子荧光、变温紫外、粒度分布等手段对聚合物进行了表征,并以紫杉醇为模型药物分子,进行了药物...以卟啉衍生物为内核,采用可逆加成-断裂链转移(RAFT)聚合法合成了温度敏感性聚己内酯-聚N-异丙基丙烯酰胺。用FT-IR、1 H NMR、GPC、TEM、分子荧光、变温紫外、粒度分布等手段对聚合物进行了表征,并以紫杉醇为模型药物分子,进行了药物释放测试。结果表明,聚合物自组装后,形成了平均直径为100nm左右的胶束。这种内部亲脂外部亲水的核壳结构能够稳定地载药,在温度为15℃的DMF中,12h内释放了37%的药物,而在温度为38℃的DMF中,12h药物释放量为81.4%。这种两亲性大分子聚合材料对紫杉醇的释放具有温度敏感性,有望在抗癌药物的控制释放领域得到广泛应用。展开更多
文摘The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measured d n /d c of the solution decreases regularly and smoothly with increasing temperature until to the specific coil globule transition temperature of PNIPAM (around 32 ℃) and afterwards it increases with increasing temperature on the contrary. This extraordinary phenomenon is successfully explained and treated by a quantitative theory in terms of accompanying solvation desolvation process in the course of coil globule transition of the polymer chain in solution.
文摘以卟啉衍生物为内核,采用可逆加成-断裂链转移(RAFT)聚合法合成了温度敏感性聚己内酯-聚N-异丙基丙烯酰胺。用FT-IR、1 H NMR、GPC、TEM、分子荧光、变温紫外、粒度分布等手段对聚合物进行了表征,并以紫杉醇为模型药物分子,进行了药物释放测试。结果表明,聚合物自组装后,形成了平均直径为100nm左右的胶束。这种内部亲脂外部亲水的核壳结构能够稳定地载药,在温度为15℃的DMF中,12h内释放了37%的药物,而在温度为38℃的DMF中,12h药物释放量为81.4%。这种两亲性大分子聚合材料对紫杉醇的释放具有温度敏感性,有望在抗癌药物的控制释放领域得到广泛应用。
