在反尖晶石型空心磁性Fe3O4纳米粒子表面修饰上APTES，然后通过化学交联法包覆上聚丙烯酸（PAA）制备了pH敏感性PAA@Fe3O4复合空心纳米粒子。用透射电子显微镜（TEM）、振动样品磁强计（VSM）、纳米粒度仪、傅里叶变换红外光谱仪和紫外分光光度计对包覆前后的形貌、结构、磁性和包覆率进行表征。并用罗丹明6G（R6G）作为模拟药物进行药物负载和释放性能进行体外实验研究。结果表明，所制备的PAA@Fe3O4复合粒子具有良好的磁学性能，负载药物为1011 mg/g。复合磁粒上的R6G药物释放的最大释放比达到93.0%, 这种药物控释属于一级释放曲线，同时探讨了基于分子溶解度的可能机理。这种基于磁性纳米粒子和高分子材料的复合药物负载体系，有助于提高药物的靶向递送性能并改善诊疗效率。

The surface of hollow nanoparticles of magnetite (Fe3O4) with an inverse spinel structure was modified by (3-aminopropyl)-triethoxysilane (APTES), followed by coating with polyacrylic acid (PAA) to synthesize pH-sensitive, composite Fe3O4@PAA, hollow magnetic nanoparticles (HMNPs) via chemical crosslinking. The morphology, structure, magnetism, encapsulation ratio before and after encapsulation were analyzed by transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), laser particle size analysis, Fourier transform infrared (FT-IR) spectrometry, and ultraviolet (UV) spectrophotometry techniques., Drug loading and drug release efficiencies of these nanocomposites were investigated in vitro by using rhodamine 6G (R6G) as a model drug. The composite Fe3O4@PAA nanoparticles showed excellent magnetic property, and T maximum adsorption capacity was found to be 1011 mg R6G per 1.00 g Fe3O4@PAA nanoparticles. The maximum drug delivery rate for R6G release from the composite magnetic particles was 93.0%, and the drug delivery dynamics followed first-order kinetics. Additionally, the possible mechanism based on molecular solubility was explored. The results demonstrated that the composite drug loading system, based on magnetic nanoparticles and polymer materials could help to enhance the performance of targeted drug delivery and improve the efficiency of diagnosis and treatment.

国家自然科学基金（61102031）；湖南省科技厅重点项目（2013SK2003）