磁性热敏聚合物微球的制备及磁感应控制释放行为

采用种子乳液聚合法在Fe3O4纳米粒子表面聚合包覆N-异丙基丙烯酰胺(NIPAM)与α-甲基丙烯酸(MAA)的共聚物,制备了磁性热敏聚合物微球Fe3O4/P(NIPAM-co-MAA).利用广角X射线衍射仪(WAXD)、透射电子显微镜(TEM)、zeta粒度仪(DLS)、热重分析(TGA)、振动样品磁力计(VSM)及比表面积测试仪(BET)等对微球的结构与形貌进行了表征,通过紫外-可见光分光光度法(UV-Vis)研究了微球对水溶性模型药物罗丹明B(RhB)的负载和磁感应控制释放行为.结果表明,微球粒径为80～200 nm,比表面积约为30.04m2/g,平均孔径约为24.50 nm;微球中聚合物含量约为73 wt%,磁粒子含量约为20 wt%,饱和磁感应强度为16.49 emu/g,其体积相转变温度(VPTT)约为37.5℃.RhB在微球中的装载量可以达到16.38 mg/g;在外加交变磁场作用下,RhB在模拟肠液和胃液中的磁感应释放量分别达到10.47和13.02 mg/g.

SYNTHESIS OF MAGNETIC THERMO-SENSITIVE POLYMERIC MICROSPHERES FOR CONTROLLED RELEASE VIA MAGNETIC INDUCTION

Seed emulsion polymerization was carried out to encapsulate Fe3O4nanoparticles with poly(N-isopropylacrylamide-co-methacrylic acid) for preparing polymeric microspheres(Fe3O4/P(NIPAM-co-MAA)) possessing magnetic and thermo-sensitive responses.The structure and morphology of microspheres were characterized by wide-angle X-ray diffraction(WAXD),transmission electron microscopy(TEM),dynamic light scattering(DLS),thermogravimetric analysis(TGA),vibrating specimen magnetometry(VSM) and BET specific surface area measurements.Ultraviolet-visible light(UV-Vis) spectroscopy was employed to investigate the drug loading and release behavior of microspheres using rhodamine B(RhB) as a model drug.It is indicated that the diameters of microspheres range from 80 nm to 200 nm,the specific surface area and average pore diameter are about 30.04 m2/g and 24.50 nm,respectively.The polymer content and Fe3O4 content of microspheres are about 73 wt% and 20 wt%,respectively.The saturated magnetization of microspheres reaches 16.49 emu/g,and the volume phase transition temperature(VPTT) is about 37.5℃.The RhB loading amount of microspheres is able to reach 16.38 mg/g.Under alternating magnetic field,the RhB release amount reaches 13.02 mg/g in simulative gastric-juice,and 10.47 mg/g in simulative intestinal-juice,respectively.Therefore,the synthesized polymeric microspheres(Fe3O4/P(NIPAM-co-MAA)) can be used as drug-carrier,and demonstrate good prospect in the targeted drug and drug controlled release.