磁性温敏复合微球的制备及磁场作用下的药物缓释行为

Preparation of Magnetic Temperature-responsive Composite Microspheres and Their Drug-release Behaviors under an AC Magnetic Field

摘要:

采用无皂乳液聚合的方法将Fe3O4与温敏性N-异丙基丙烯酰胺-丙烯酰胺共聚物复合，制备了具有核壳结构的磁性温敏复合微球，并研究了其在60kHz、6.5kA/m交变磁场作用下的磁热性能和药物缓释行为。结果表明，所制备的Fe3O4/(PNIPAAm-co-Am)复合微球具有良好的磁热性能，20min内即可使自身温度升高到温敏聚合物的LCST（~42°C）。复合微球在连续和间歇磁场作用下的药物释放行为显示，间歇性施加磁场不仅延长药物的释放周期、而且能够增大药物的积累释放量。因具有良好的磁热和药物缓释性能，本研究所制备的聚合物微球有望同步实现肿瘤热疗和化疗药物的可控释放。

Abstract:

Magnetic and temperature-responsive polymer microspheres, consisting of superparamagnetic Fe3O4 nanopaticles and temperature-responsive poly(N-isopropylacrylamide-co-acrylamide) (PNIPAAm-co-Am) microgel, were prepared by soap-free emulsion free copolymerization. Their heating generation abilities and drug release behaviors were investigated under an AC magnetic field of 60kHz and 6.5kA/m. Results showed that the as-synthesized Fe3O4/(PNIPAAm-co-Am) composite microspheres exhibited high heating generation ability. The temperature of 42°C, which is close to the lower critical solution temperature (LCST) of the temperature-responsive polymer, was achieved after the composite microspheres were exposed to an AC magnetic field for 20min. The drug release profiles showed that longer release duration and larger overall release could be achieved by intermittent application of a magnetic field as compared to continuous magnetic field. With high heating generation ability and controlled drug release property, such Fe3O4/(PNIPAAm-co-Am) polymer microspheres are promising for the combination of tumor hyperthermia and controlled release of chemotherapy drugs.