温度敏感型树枝状大分子衍生物的合成及药物控制释放

通过加入偶联剂活化末端羧基基团进行酰胺化反应, 将得到的带有羧基末端基团的温敏性聚N-异丙基丙烯酰胺接枝到整代的树枝状大分子聚酰胺-胺(PAMAM)上, 制备了树枝状大分子衍生物PAMAM-g-PNIPAm, 通过FTIR和¹H NMR表征其结构, 通过GPC和¹H NMR测定其分子量, 从而验证了接枝产物的形成; 通过紫外-可见分光光度计测定其在不同pH值缓冲液中的低临界溶胀/溶解温度(LCST)值, 发现产物的LCST值受缓冲液pH值的影响很大, 接枝前后的LCST值也发生了变化. 选用难溶性药物吲哚美辛作为模型药物, 考察了树枝状大分子及其温度敏感性衍生物PAMAM-g-PNIPAm作为载体对药物的包载、增溶和不同温度环境下的释放行为. 结果表明, 树枝状大分子衍生物对吲哚美辛具有增溶和控制释放的性能, 在难溶性药物的控制释放领域具有广阔的应用前景.

Synthesis and Drug Release Behavior of Thermosensitive Dendrimer Derivatives

The thermosensitve polymer was grafted to the polyamidoamine(PAMAM) dendrimer using EDC•HCl. The structure of the dendrimer derivative was characterized by FTIR and 1H NMR and the mole-cular weight was determined by GPC and 1H NMR, which indicates that the grafted polymer was synthesized successfully. The thermosensitve properties determined by UV-Vis photometer showed that the LCST was changed in different medium. Using indomethacin as a model drug, the behavior of the temperature controlled drug release from this novel polymer derivative have been studied. The results show that the rate of the drug release can be effectively controlled by the surrounding temperature, and the solubility of the drug is also increased. The new drug carrier is desirable to make a great effect in the drug delivery system.