温敏型智能化靶向式药物载体研究（I）——具有温敏开关的多孔膜

研究了膜孔内接枝聚异丙基丙烯酰胺 (PNIPAM)“开关”的温敏型智能膜的制备 ,并对其进行了温度感应开关性能实验。实验中采用等离子体接枝填孔聚合法将 PNIPAM接枝在多孔平板膜的膜孔中 ,结果表明 ,这种接枝了 PNIPAM“开关”的多孔膜具有温度感应特性 ,其利用膜孔内 PNIPAM接枝链的膨胀 -收缩特性实现了感温性开关性能。当环境温度低于 PNIPAM的低临界溶解温度 (L CST)时 ,膜孔内 PNIPAM分子链膨胀而使膜孔呈“关闭”状态 ;而当环境温度高于 L CST时 ,PNIPAM分子链变为收缩状态而使膜孔“开启”。温敏开关的 L CST可通过添加丙烯酰胺 (AAM)与异丙基丙烯酰胺 (NIPAM)共聚来调节 ,AAM与 NIPAM共聚开关的 L CST随 AAM添加量的增加而单调上升。

Study on Thermo-sensitive Intelligent Targeting Type Drug Carriers (I) Porous Membranes with Grafted Thermo-sensitive Gates

Thermo-responsive intelligent membranes with linear grafted poly(N-isopropylacrylam- ide) (PNIPAM) gates on the inner pore surface were prepared, and experiments were carried out on the thermo-responsive gating characteristics. Plasma-graft pore-filling polymerization was used to graft PNIPAM into the pore of the porous flat membranes. The experimental results showed that PNIPAM-grafted PVDF (PNIPAM-g-PVDF) membranes were featured with thermo-responsiveness due to the thermo-responsive swollen-shrunken property of PNIPAM chains grafted on the inner pore surface of the membrane. At temperatures below the lower critical solution temperature (LCST), the linear grafted PNIPAM chains on the inner pore surface were in the swollen state, and the pores in the membrane were closed; in contrast, the grafted PNIPAM chains were in the shrunken state at temperatures above the LCST, and therefore the pores in the membrane were open. The LCST of the thermo-sensitive gates could be adjusted by adding acrylamide (AAM) in the N-isopropylacrylamide (NIPAM) monomer solution, the LCST of the poly(NIPAM-co-AAM) gates increased simply with the increase of the AAM fraction.