Department of Cell Biology and Morphology, University of Lausanne, Rue du Bugnon 9, CH-1005 Lausanne, Switzerland.
ACS Nano. 2012 Feb 28;6(2):1176-87. doi: 10.1021/nn203822t. Epub 2012 Feb 8.
Ion imaging is a powerful methodology to assess fundamental biological processes in live cells. The limited efficiency of some ion-sensing probes and their fast leakage from cells are important restrictions to this approach. In this study, we present a novel strategy based on the use of dendrimer nanoparticles to obtain better intracellular retention of fluorescent probes and perform prolonged fluorescence imaging of intracellular ion dynamics. A new sodium-sensitive nanoprobe was generated by encapsulating a sodium dye in a PAMAM dendrimer nanocontainer. This nanoprobe is very stable and has high sodium sensitivity and selectivity. When loaded in neurons in live brain tissue, it homogenously fills the entire cell volume, including small processes, and stays for long durations, with no detectable alterations of cell functional properties. We demonstrate the suitability of this new sodium nanosensor for monitoring physiological sodium responses such as those occurring during neuronal activity.
离子成像技术是评估活细胞中基本生物过程的强大方法。一些离子感应探针的效率有限，并且容易从细胞中快速漏出，这是该方法的重要限制。在这项研究中，我们提出了一种基于使用树枝状聚合物纳米粒子的新策略，以获得更好的荧光探针在细胞内的保留，并对细胞内离子动力学进行长时间荧光成像。通过将钠离子染料封装在 PAMAM 树枝状聚合物纳米容器中，生成了一种新的钠离子敏感染料纳米探针。这种纳米探针非常稳定，具有高的钠离子灵敏度和选择性。当装载在活脑组织中的神经元中时，它均匀地充满整个细胞体积，包括小的突起，并且可以长时间保留，而不会检测到细胞功能特性的任何改变。我们证明了这种新型钠离子纳米传感器非常适合监测生理钠离子响应，例如神经元活动期间发生的那些响应。
