Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239, Krakow, Poland.
Institute of Biology, Pedagogical University of Cracow, Podchorazych 2, PL-30084, Krakow, Poland.
Colloids Surf B Biointerfaces. 2017 Dec 1;160:429-437. doi: 10.1016/j.colsurfb.2017.09.042. Epub 2017 Sep 20.
The preparation of stable cysteine-capped silver nanoparticles (AgNPs), via the reduction of silver ions with sodium borohydride and modification of formed nanoparticles by l-cysteine, was developed. The micrographs from transmission electron microscopy (TEM) revealed that the spherical AgNPs exhibited an average size equal to 22±4nm. Surface enhanced Raman spectroscopy (SERS) and inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed a chemisorption of cysteine molecules on the AgNPs. Additionally, dynamic light scattering (DLS) measurements showed that the AgNPs were stable for ionic strength lower than 5×10molL and at 6.8<pH<4.5. The electrophoretic mobility measurements allowed to determine the isoelectric point of AgNPs, which appeared at pH 5.1. Below this value, the AgNPs were positively charged with the zeta potential equal to +68±3mV at pH 3.5. Under alkaline condition, the zeta potential of AgNPs was negative, attaining a value of -71±3mV at pH 9.5. The AgNPs were prone to the processes of oxidative dissolution, which was assessed using atomic absorption spectrometry (AAS). The cytotoxicity of AgNPs towards histiocytic lymphoma (U-937) and human promyelocytic (HL-60) cells was studied by the evaluation of changes in mitochondrial functions and cell membrane integrity. In the case of the HL-60 cells, apoptosis caused by the membrane damage was dominant. Furthermore, the obtained results showed the does-dependent impact of the AgNPs on the cell viability. Finally, it was found that the AgNP concentration of 15mgL caused a complete destruction of cells of both types.
通过硼氢化钠还原银离子，并通过半胱氨酸对形成的纳米颗粒进行修饰，制备了稳定的半胱氨酸封端的银纳米颗粒（AgNPs）。透射电子显微镜（TEM）的显微照片显示，球形 AgNPs 的平均粒径等于 22±4nm。表面增强拉曼光谱（SERS）和电感耦合等离子体发射光谱（ICP-OES）证实了半胱氨酸分子在 AgNPs 上的化学吸附。此外，动态光散射（DLS）测量表明，AgNPs 在离子强度低于 5×10molL 和 pH6.8<4.5 的情况下稳定。电泳迁移率测量允许确定 AgNPs 的等电点，其在 pH 5.1 时出现。在此值以下，AgNPs 带正电荷，在 pH 3.5 时的zeta 电位等于+68±3mV。在碱性条件下，AgNPs 的 zeta 电位为负，在 pH 9.5 时达到-71±3mV。AgNPs 容易发生氧化溶解过程，这可以通过原子吸收光谱（AAS）进行评估。通过评估线粒体功能和细胞膜完整性的变化，研究了 AgNPs 对组织细胞淋巴瘤（U-937）和人早幼粒细胞（HL-60）细胞的细胞毒性。在 HL-60 细胞中，以膜损伤引起的细胞凋亡为主。此外，所得结果表明 AgNPs 对细胞活力具有剂量依赖性的影响。最后，发现 AgNP 浓度为 15mgL 会导致两种类型的细胞完全破坏。
