接枝聚合物PAA—g—PIPA微球的制备及其温控释药研究

采用自由基溶液聚合法合成出Ｎ－异丙基丙烯酰胺齐聚物（Ｐｏｌｙ—Ｎ—Ｉｓｏｐｒｏｐｙｌａｍｉｄｅ，ＰＩＰＡ）．通过缩合将ＰＩＰＡ接枝在聚烯丙胺盐酸盐（Ｐｏｌｙａ－ｌｌｙａｍｉｎｅｈｙｄｒｏｃｈｌｏｒｉｄｅ，ＰＡＡ）上得到接枝聚合物ＰＡＡ—ｇ—ＰＩＰＡ．用化学交联法将ＰＡＡ－ｇ－ＰＩＰＡ制备成１０μｍ左右的微球．所得微球通过物理法吸附阿霉素（Ａｄｒｉａｍｙｃｉｎ，ＡＤ）后，采用动力学透析法测定其体外释药性能．实验数据拟合数学模型得到表征药物微球的释药特性的药物扩散系数Ｋｍ．Ｋｍ在３０℃—４５℃范围内随温度的升高而增大，反映了载药ＰＡＡ—ｇ—ＰＩＰＡ微球具有温控释药性．

PREPARATION AND RELEASING BEHAVIOUR OF TEMPERATURE RESPONSIVENESS OF GRAFT COPOLYMER PAA-g-PIPA MICROSPHERES

ligomer poly (N - isopropylacrylamide) has been made up with azobisisobutyronitrile (AIBN ) as initiator and methonal as solvent. Graft copolymer PAA-g-PIPA could be prepared by graft polymerization of PIPA onto the chain ofpolyallylamine hydrochloride (PAA ) with 3 - ethyl - 3 (3 - dimethylaminopropyl.) - carbodiimidehydrochlorid(EDC ) as condensation agent. Microspheres with size range of 10μm or so could be made of graft copolymer PAA- g - PIPA with glutaraldehyde(GA ) as cross- link agent in water/ oil system. Antitumer drug adriamycin(AD ) can be carried on the PAA- g- PIPA microspheres by physical adsorption. In vitro drug release behaviour of drug - carrying PAA- g- PIPA microspheres was examinied by dynamic dialysis technique. Data from dialysis experiment were treated with a computer after setting a methematical model which can provide a quantitative assessment of drug release. The drug release rate constant Km of drug-carrying PAA-g-PIPA microspheres were achieved. It has been shown that Km of PAA-gPIPA microspheres representing the specificity of drug release increased with increasing the temperature in the range of 30 -45 ℃. This indicated that drug release of drugcarrying PAA- g - PIPA microspheres was obviously temperature responsive.