Naito Mitsuru, Azuma Ryota, Takemoto Hiroyasu, Hori Mao, Yoshinaga Naoto, Osawa Shigehito, Kamegawa Rimpei, Kim Hyun Jin, Ishii Takehiko, Nishiyama Nobuhiro, Miyata Kanjiro, Kataoka Kazunori
a Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo , Tokyo , Japan.
b Department of Materials Engineering , Graduate School of Engineering, The University of Tokyo , Tokyo , Japan.
J Biomater Sci Polym Ed. 2017 Jul-Aug;28(10-12):1109-1123. doi: 10.1080/09205063.2017.1301775. Epub 2017 Mar 12.
Surface functionalization of nanoparticles is a crucial factor for nanoparticle-mediated drug and nucleic acid delivery. Particularly, the density of targeting ligands on nanoparticle significantly affects the affinity of nanoparticles to specific cellular surface (or receptor) through the multivalent binding effect. Herein, multilayered polyion complexes (mPICs) are prepared to possess varying densities of cyclic RGD peptide (cRGD) ligands for cancer-targeted small interfering RNA (siRNA) delivery. A template PIC is first prepared by mixing siRNAs with homo catiomers of N-substituted polyaspartamide bearing tetraethylenepentamine (PAsp(TEP)) in aqueous solution, followed by silica-coating through silicate condensation reaction. Then, silica-coated PICs (sPICs) are further covered with block catiomers of PAsp(TEP) and poly(ethylene glycol) (PEG) equipped with cRGD ligand. Successful preparation of targeted mPICs is confirmed from the changes in size and ζ-potential and the elemental analysis by transmission electron microscopy. Notably, the number of cRGD ligands per mPIC is regulated by altering the silicate concentration upon preparation of sPICs, which is confirmed by fluorescence correlation spectroscopy using fluorescent-labeled block catiomers. Ultimately, the targeted mPICs with a higher number of cRGD ligands demonstrate more efficient cellular uptake in cultured cancer cells, leading to enhanced gene silencing activity.
纳米颗粒的表面功能化是纳米颗粒介导的药物和核酸递送的关键因素。特别是，纳米颗粒上靶向配体的密度通过多价结合效应显著影响纳米颗粒与特定细胞表面（或受体）的亲和力。在此，制备多层聚离子复合物（mPICs）以具有不同密度的环状RGD肽（cRGD）配体，用于癌症靶向小干扰RNA（siRNA）递送。首先通过在水溶液中将siRNA与带有四乙烯五胺的N-取代聚天冬酰胺的均相阳离子聚合物（PAsp(TEP)）混合来制备模板PIC，然后通过硅酸盐缩合反应进行二氧化硅包覆。然后，用配备有cRGD配体的PAsp(TEP)和聚乙二醇（PEG）的嵌段阳离子聚合物进一步覆盖二氧化硅包覆的PIC（sPICs）。通过尺寸和ζ电位的变化以及透射电子显微镜的元素分析证实了靶向mPICs的成功制备。值得注意的是，每个mPIC上cRGD配体的数量通过在制备sPICs时改变硅酸盐浓度来调节，这通过使用荧光标记的嵌段阳离子聚合物的荧光相关光谱得到证实。最终，具有更多cRGD配体的靶向mPICs在培养的癌细胞中表现出更有效的细胞摄取，从而导致增强的基因沉默活性。
