Cho Eun Chul, Xie Jingwei, Wurm Patricia A, Xia Younan
Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130, USA.
Nano Lett. 2009 Mar;9(3):1080-4. doi: 10.1021/nl803487r.
This Letter presents a new method for differentiating the Au nanospheres attached to the cell surface from those being internalized into the cells. We introduced an etching solution based on I2 and KI that can selectively dissolve the Au nanospheres on the cell surface within a short period of time. The advantage of this etchant is its low toxicity to the cells because it is capable of etching away a relatively large amount of Au nanospheres at a low molar concentration. By combining with quantitative elemental analysis, we found that the deposition of Au nanospheres on the surface of cancer cells was highly dependent on the sign of surface charges on the Au nanospheres. In addition, by fitting the uptake data with a kinetic model, we were able to derive the overall and internalization rate constants for Au nanospheres and both of them were found to be governed by the surface charges on Au nanospheres.
这封信介绍了一种区分附着在细胞表面的金纳米球与内化到细胞内的金纳米球的新方法。我们引入了一种基于I2和KI的蚀刻溶液，它可以在短时间内选择性地溶解细胞表面的金纳米球。这种蚀刻剂的优点是对细胞毒性低，因为它能够在低摩尔浓度下蚀刻掉相对大量的金纳米球。通过与定量元素分析相结合，我们发现金纳米球在癌细胞表面的沉积高度依赖于金纳米球表面电荷的符号。此外，通过用动力学模型拟合摄取数据，我们能够推导出金纳米球的总体摄取速率常数和内化速率常数，并且发现它们都受金纳米球表面电荷的支配。
