水滑石型磁性纳米载药粒子的制备及其体外药物释放性能研究

Synthesis and Drug Release Behavior of Magnetic Nanoparicles Based on Layered Double Hydroxide for Magnetic Drug Targeting

通过调变镁铁尖晶石的含量,采用一步共沉淀法制备了一系列具有核壳结构的水滑石型磁性纳米载药粒子,对其微结构、热稳定性、磁性和药物释放性能进行了系统的研究.结果表明这种磁性纳米载药粒子是一种具有以镁铁尖晶石为核层、双氯酚酸(Diclofenac,DIC)插层水滑石(DIC-LDH)为壳层的复合纳米粒子,粒径在90～180 nm之间.其中壳层DIC-LDH的晶粒尺寸D110和层板电荷密度随磁核含量的增大而逐渐减小.磁性纳米载药粒子的载药量随磁核含量的增大而逐渐减小,而其比饱和磁化强度则随着磁核含量的增大逐渐增大.体外释放实验表明,无外加磁场时,磁核含量增大,壳层DIC-LDH粒径减小,磁性纳米载药粒子药物释放速率逐渐增大;外加1500 G磁场时,磁核含量增大,磁致团聚程度增大,其药物释放速率逐渐减小.

By tuning the contents of magnesium ferrite,a series of magnetic nanoparitcles based on layered double hydroxide（LDH） for magnetic drug targeting were prepared via a one step coprecipitation method.The microstructure,thermal stability,magnetism and drug release properties of these magnetic nanoparitcles were systematically investigated.It is found that the magnetic nanoparticles possess core-shell structure with diclofenac intercalated LDH（DIC-LDH） shell coated on the surface of magnesium ferrite core.The Scherrer particle size and the layer charge density of the coated DIC-LDH,the drug loading of the magnetic nanopar-ticles decrease gradually with increasing magnesium ferrite content,while their saturation magnetizations show the inverse trend.Under no magnetic field（MF）,the magnetic nanoparticles show enhanced drug re-lease rate with increasing magnesium ferrite content due to the decreased particle size of the coated DIC-LDH.Under a 1500 G MF,the release rate reduces gradually with increasing magnesium ferrite con-tents due to the instantly aggregation of the magnetic nanoparticles induced by the MF.