Wang Lu, Yang Cai-qin, Wang Jing
School of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017, China.
Yao Xue Xue Bao. 2011 May;46(5):592-8.
Effects of different procedures of magnetic nanoparticles into the liposome structure on the distribution of magnetic particles in the liposome were investigated. Magnetic liposomes with high-encapsulating rate of cisplatin (CDDP) were obtained. Fe3O4 magnetic nanoparticles which was modified by organic functional group on surface was synthesized by an one-step modified hydrothermal method. The CDDP magnetic liposomes were prepared by a film scattering-ultrasonic technique and the concentrations of CDDP in the liposomes were measured by graphite furnace atomic absorbance spectroscopy. Magnetic liposomes with different microstructure were prepared by the two different procedures, where the magnetic particles were combined with phospholipid before the film preparation to form liposome in procedure I, and drug solution and the magnetic particles were mixed before hydrating the lipids film to form liposome in procedure II. The liposome structure was observed by transmission electron microscope (TEM). The CDDP magnetic liposomes were prepared by the optimized method which was selected by orthogonal test. Encapsulation rate of the magnetic particles distributed in the phospholipid bilayer through the procedure I was 34.90%. While liposome, produced by the procedure II technique, contained magnetic particles in the interior aqueous compartment, which encapsulation rate was 28.34%. Encapsulation rates of both I and II were higher than that of conventional liposome. The release profile of all the three different liposomes in vitro fitted with a first-order equation. Because of distribution of magnetic particles in the phospholipid bilayer, the skeleton of phospholipid bilayer was changed. The releasing tl/2 of magnetic liposomes produced by the procedure I technique is 9 h, which is shorter than that of the other two liposomes. Assemble of magnetic nanoparticles into the structure of liposome was succeeded by the procedure I, which showed superiority than by procedure II whatever in CDDP liposome encapsulation efficiency and content of the magnetic particles and would ensure sustained-release character.
研究了将磁性纳米颗粒引入脂质体结构的不同方法对磁性颗粒在脂质体中分布的影响。制备了顺铂（CDDP）包封率高的磁性脂质体。采用一步改性水热法合成了表面经有机官能团改性的Fe3O4磁性纳米颗粒。通过薄膜分散-超声技术制备了CDDP磁性脂质体，并用石墨炉原子吸收光谱法测定了脂质体中CDDP的浓度。通过两种不同方法制备了具有不同微观结构的磁性脂质体，在方法I中，磁性颗粒在制膜前与磷脂结合形成脂质体；在方法II中，药物溶液和磁性颗粒在水化脂质膜前混合形成脂质体。通过透射电子显微镜（TEM）观察脂质体结构。通过正交试验选择优化方法制备了CDDP磁性脂质体。通过方法I分布在磷脂双分子层中的磁性颗粒包封率为34.90%。而通过方法II技术制备的脂质体，磁性颗粒存在于内部水相隔室中，其包封率为28.34%。方法I和方法II的包封率均高于传统脂质体。三种不同脂质体的体外释放曲线均符合一级方程。由于磁性颗粒分布在磷脂双分子层中，磷脂双分子层的骨架发生了变化。方法I技术制备的磁性脂质体的释放半衰期为9 h，短于其他两种脂质体。方法I成功地将磁性纳米颗粒组装到脂质体结构中，在CDDP脂质体包封效率和磁性颗粒含量方面均显示出比方法II更优越的性能，并能确保缓释特性。
