Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi'an 710072, China.
J Colloid Interface Sci. 2013 May 15;398:51-8. doi: 10.1016/j.jcis.2013.01.042. Epub 2013 Feb 24.
In this work, Fe3O4/P(acrylic acid-methyl methacrylate-N-isopropylacrylamide) (Fe3O4/P(AA-MMA-NIPAm)) thermoresponsive magnetic composite microspheres have been prepared by controlled radical polymerization in the presence of 1,1-diphenylethene (DPE). The shell thickness of thermosensitive polymer (PNIPAm), which was on the surface of the microspheres, can be controlled by using DPE method. The morphology and thermosensitive properties of the composite microspheres, polymerization mechanism of the shell were characterized by TEM, FTIR, VSM, Laser Particle Sizer, TGA, NMR, and GPC. The microspheres with narrow particle size distribution show high saturation magnetization and superparamagnetism. The thermosensitive properties of the composite microspheres can be adjusted indirectly via controlling the addition amount of monomer (NIPAm) in the second step during controlled radical polymerization. Phenolphthalein was chosen as a model drug to investigate drug release behavior of the thermoresponsive magnetic composite microspheres with different shell thickness. Controlled drug release testing reveals that the release behavior depends on the thickness of polymer on the surface of the microspheres.
在这项工作中，通过 1,1-二苯乙烯（DPE）存在下的可控自由基聚合制备了 Fe3O4/P（丙烯酸-甲基丙烯酸甲酯-N-异丙基丙烯酰胺）（Fe3O4/P（AA-MMA-NIPAm））温敏磁性复合微球。通过 DPE 法可以控制位于微球表面的温敏聚合物（PNIPAm）的壳层厚度。通过 TEM、FTIR、VSM、激光粒度仪、TGA、NMR 和 GPC 对复合微球的形貌和温敏性能、聚合机理进行了表征。具有较窄粒径分布的微球表现出高的饱和磁化强度和超顺磁性。通过控制第二步可控自由基聚合中单体（NIPAm）的添加量，可以间接调节复合微球的温敏性能。选择酚酞作为模型药物，研究了不同壳层厚度的温敏磁性复合微球的药物释放行为。控制药物释放测试表明，释放行为取决于微球表面聚合物的厚度。
