Schrand Amanda M, Braydich-Stolle Laura K, Schlager John J, Dai Liming, Hussain Saber M
Applied Biotechnology Branch, Human Effectiveness Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, 45433-5707, USA. Department of Chemical and Materials Engineering, University of Dayton, 300 College Park, Dayton, OH 45469-0160, USA.
Nanotechnology. 2008 Jun 11;19(23):235104. doi: 10.1088/0957-4484/19/23/235104. Epub 2008 May 6.
Silver (Ag) nanoparticles have unique plasmon-resonant optical scattering properties that are finding use in nanomedical applications such as signal enhancers, optical sensors, and biomarkers. In this study, we examined the chemical and biological properties of Ag nanoparticles of similar sizes, but that differed primarily in their surface chemistry (hydrocarbon versus polysaccharide), in neuroblastoma cells for their potential use as biological labels. We observed strong optical labeling of the cells in a high illumination light microscopy system after 24 h of incubation due to the excitation of plasmon resonance by both types of Ag nanoparticle. Surface binding of both types of Ag nanoparticle to the plasma membrane of the cells was verified with scanning electron microscopy as well as the internalization and localization of the Ag nanoparticles into intracellular vacuoles in thin cell sections with transmission electron microscopy. However, the induction of reactive oxygen species (ROS), degradation of mitochondrial membrane integrity, disruption of the actin cytoskeleton, and reduction in proliferation after stimulation with nerve growth factor were found after incubation with Ag nanoparticles at concentrations of 25 µg ml(-1) or greater, with a more pronounced effect produced by the hydrocarbon-based Ag nanoparticles in most cases. Therefore, the use of Ag nanoparticles as potential biological labels, even if the surface is chemically modified with a biocompatible material, should be approached with caution.
银（Ag）纳米颗粒具有独特的等离子体共振光学散射特性，正被应用于纳米医学领域，如信号增强剂、光学传感器和生物标志物。在本研究中，我们检测了大小相似但主要在表面化学性质（碳氢化合物与多糖）上存在差异的银纳米颗粒在神经母细胞瘤细胞中的化学和生物学特性，以评估其作为生物标记物的潜在用途。在高照明光学显微镜系统中，经过24小时孵育后，由于两种类型的银纳米颗粒均能激发等离子体共振，我们观察到细胞出现强烈的光学标记。通过扫描电子显微镜证实了两种类型的银纳米颗粒均与细胞的质膜发生表面结合，同时利用透射电子显微镜在薄细胞切片中观察到银纳米颗粒内化并定位到细胞内液泡中。然而，在与浓度为25 μg ml⁻¹或更高的银纳米颗粒孵育后，发现会诱导活性氧（ROS）生成、破坏线粒体膜完整性、扰乱肌动蛋白细胞骨架以及在神经生长因子刺激后细胞增殖减少，在大多数情况下，基于碳氢化合物的银纳米颗粒产生的影响更为明显。因此，即使银纳米颗粒表面用生物相容性材料进行了化学修饰，将其用作潜在生物标记物时也应谨慎对待。
