Shin Da Hye, Heo Min Beom, Lim Yong Taik
Center for Chemical analysis, Korea Research Institute of Chemical Technology (KRICT), Daejeon 305-600, Korea.
SKKU Advanced Institute of Nanotechnology (SAINT), School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Korea.
Molecules. 2015 Mar 9;20(3):4369-82. doi: 10.3390/molecules20034369.
In this work, we describe the fabrication of self-assembled polyelectrolyte nanoparticles that provide a multicolor optical imaging modality. Poly(γ-glutamic acid)(γ-PGA) formed self-assembled nanoparticles through electrostatic interactions with two different cationic polymers: poly(L-lysine)(PLL) and chitosan. The self-assembled γ-PGA/PLL and γ-PGA/chitosan nanoparticles were crosslinked by glutaraldehyde. Crosslinking of the ionic self-assembled nanoparticles with glutaraldehyde not only stabilized the nanoparticles but also generated a strong autofluorescence signal. Fluorescent Schiff base bonds (C=N) and double bonds (C=C) were generated simultaneously by crosslinking of the amine moiety of the cationic polyelectrolytes with monomeric glutaraldehyde or with polymeric glutaraldehyde. The unique optical properties of the nanoparticles that resulted from the crosslinking by glutaraldehyde were analyzed using UV/Vis and fluorescence spectroscopy. We observed that the fluorescence intensity of the nanoparticles could be regulated by adjusting the crosslinker concentration and the reaction time. The nanoparticles also exhibited high performance in the labeling and monitoring of therapeutic immune cells (macrophages and dendritic cells). These self-assembled nanoparticles are expected to be a promising multicolor optical imaging contrast agent for the labeling, detection, and monitoring of cells.
在本研究中，我们描述了一种自组装聚电解质纳米颗粒的制备方法，该纳米颗粒可提供多色光学成像模式。聚（γ-谷氨酸）（γ-PGA）通过与两种不同的阳离子聚合物：聚（L-赖氨酸）（PLL）和壳聚糖的静电相互作用形成自组装纳米颗粒。自组装的γ-PGA/PLL和γ-PGA/壳聚糖纳米颗粒通过戊二醛交联。离子自组装纳米颗粒与戊二醛的交联不仅使纳米颗粒稳定，还产生了强烈的自发荧光信号。阳离子聚电解质的胺部分与单体戊二醛或聚合戊二醛交联，同时产生荧光席夫碱键（C=N）和双键（C=C）。使用紫外/可见光谱和荧光光谱分析了戊二醛交联导致的纳米颗粒独特光学性质。我们观察到，通过调节交联剂浓度和反应时间，可以调节纳米颗粒的荧光强度。这些纳米颗粒在治疗性免疫细胞（巨噬细胞和树突状细胞）的标记和监测方面也表现出高性能。这些自组装纳米颗粒有望成为用于细胞标记、检测和监测的有前途的多色光学成像造影剂。
