This study reports self-assembled pullulan nanoparticles (PUNPs) obtained by the diafiltration method after dissolving phthalic pullulan in dimethylformamide, which was prepared by esterification between the primary hydroxyl groups of the pullulan and carboxylic acids of phthalic anhydride. The morphologies of the PUNPs observed by transmission electron microscopy (TEM) were spherical shapes. The particle sizes of the PUNPs measured by dynamic light scattering (DLS) were around 75.3 nm with −49.32 mV zeta potential. The ordered structure of pullulan measured by circular dichroism (CD) spectroscopy and X-ray diffraction (XRD) was enhanced by the formation of self-assembled polymeric NPs. Methylene blue (MB) used in tissue imaging agent was loaded into PUNPs via ionic bonding of cationic MB and anionic PUNPs, the CD of MB was induced in the PUNPs in the range of 500–700 nm whose crossing point matched κ_max in the UV region of MB.

本研究报道了将邻苯二甲酸支链淀粉溶于二甲基甲酰胺后，通过渗滤法获得的自组装支链淀粉纳米颗粒（PUNPs），其是通过支链淀粉的伯羟基与邻苯二甲酸酐的羧酸之间的酯化反应制备的。通过透射电子显微镜（TEM）观察到的PUNP的形态为球形。通过动态光散射（DLS）测量的PUNP的粒径约为75.3 nm，ζ电势为-49.32 mV。通过形成自组装的聚合物NP增强了通过圆二色性（CD）光谱和X射线衍射（XRD）测量的支链淀粉的有序结构。用于组织显像剂的亚甲基蓝（MB）通过阳离子MB和阴离子PUNPs的离子键合，MB的光盘中的，其交叉点匹配500-700 nm范围内的PUNPs诱导κ_最大值在MB的UV区。