Ferdous A J, Stembridge N Y, Singh M
College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee 32307-3800, USA.
J Control Release. 1998 Jan 2;50(1-3):71-8. doi: 10.1016/s0168-3659(97)00116-8.
Monensin is a carboxylic ionophore which can potentiate the activity of ricin based immunotoxins (IT) in vitro and in vivo against a variety of human tumours. Monensin was encapsulated into nanoparticles (NP) by using biodegradable poly(DL-lactide-co-glycolide) (PLGA, 50:50). The NP were prepared by modified emulsification-solvent evaporation method. High shear homogenization followed by simultaneous stirring and bath sonication were used for preparing NP. The size of NP was determined by photon correlation spectroscopy using a BI 90 particle sizer (Brookhaven Instruments). The average size of NP could be decreased from 567 nm to 163 nm by increasing the concentration of polyvinyl alcohol from 10% to 100% of PLGA. The NP were spherical in shape as observed by Atomic Force Microscopy. The concentration of monensin in the NP was analyzed by HPLC and the entrapment efficiency was found to be more than 12%. The zeta potential of NP was -25.8 (+/- 1.3) mv, which did not change significantly after resuspension of the freeze dried sample. The NP were tested against HL-60 and HT-29 human tumour cell lines in vitro. Monensin NP potentiated the activity of IT by 40 to 50 times against these cell lines. There was however, no difference between the NP and liposomes for their potentiating affect of IT against the two tumour cell lines.
莫能菌素是一种羧酸离子载体，在体外和体内均可增强基于蓖麻毒素的免疫毒素（IT）对多种人类肿瘤的活性。通过使用可生物降解的聚（DL-丙交酯-共-乙交酯）（PLGA，50:50）将莫能菌素包裹到纳米颗粒（NP）中。NP采用改良的乳化-溶剂蒸发法制备。通过高剪切均质化，随后同时搅拌和浴式超声处理来制备NP。使用BI 90粒度分析仪（布鲁克海文仪器公司）通过光子相关光谱法测定NP的大小。通过将聚乙烯醇的浓度从PLGA的10%增加到100%，NP的平均大小可从567nm降至163nm。通过原子力显微镜观察，NP呈球形。通过高效液相色谱法分析NP中莫能菌素的浓度，发现包封率超过12%。NP的ζ电位为-25.8（±1.3）mV，冻干样品重悬后该电位没有明显变化。在体外针对HL-60和HT-29人肿瘤细胞系对NP进行了测试。莫能菌素NP对这些细胞系增强IT的活性40至50倍。然而，对于IT对这两种肿瘤细胞系的增强作用，NP与脂质体之间没有差异。
