Size-tuning of self-assembled hollow particles Nano-PICsomes and application to protein delivery system

我们已经开发了新的聚离子复合物（PIC）的纳米结构制备的一组相反电荷的水溶性聚合物，主要是，嵌段共聚物组成的生物相容性聚（乙二醇）（PEG）和聚（氨基酸）在水介质中的简单混合。因此，我们建立了制备单分散中空颗粒，纳米PICsome，其特征在于通过容易地调节囊泡尺寸超过100-400 nm的直径的方法。在荷瘤小鼠中检查了各种尺寸的Nano-PIC体的详细生物分布。从药代动力学分析，直径为150-200 nm的PICsome显示出更长的血液循环。通过使用长循环Nano-PIC体作为标尺来确定区分正常和肿瘤组织的渗透性的纳米载体的临界尺寸（~150 nm）。

We have developed novel polyion complex (PIC) nano-architectures prepared by the simple mixing of a set of oppositely charged water-soluble polymers, mainly, block copolymers consisting of biocompatible poly(ethylene glycol) (PEG) and poly(amino acid)s in an aqueous medium. As a result, we established the preparation method of monodispersed hollow particles, Nano-PICsomes, which are characterized by facile tuning of vesicle size over 100-400 nm in diameter. Detailed biodistribution of the various sizes of Nano-PICsomes was examined in tumor-bearing mice. From pharmacokinetic analyses, PICsomes with the diameter of 150-200 nm showed much prolonged blood circulation. Critical size of nanocarriers (～150 nm) discriminating the permeability into normal and tumor tissues was determined by the use of long-circulating Nano-PICsome as a ruler.