Novel quartz crystal microbalance cytosensor for real-time monitoring of polystyrene nanospheres effect on cell apoptosis

Abstract

• A convenient quartz crystal microbalance (QCM) cytosensor was first developed for dynamical evaluating of polystyrene (PS) nanospheres effect on cell apoptosis. • The proposed QCM cytosensor was capable of monitoring cell volume regulatory of MDA-MB-231 cell for the evaluation of the cytotoxicity of PS nanospheres. • The study established a convenient model to evaluate the cytotoxicity of different-sized PS nanospheres. A convenient quartz crystal microbalance (QCM) cytosensor was fabricated to monitor cell volume regulatory of MDA-MB-231 cells in real time for evaluating cytotoxicity of polystyrene (PS) nanospheres of different sizes. Herein poly-l-lysine and mercaptosuccinic acid were modified onto gold electrode to capture MDA-MB-231 cells. Cell volume and cell mass are tightly linked and thus the processes of regulatory volume decrease (RVD) could be measured by monitoring the changes of cell mass dynamically. Preliminary result showed that RVD of MDA-MB-231 cells was inhibited by PS nanospheres of different sizes. And the inhibition of PS nanospheres on RVD in MDA-MB-231 cells was size-dependent. In addition, flow cytometry assay showed that apoptosis of MDA-MB-231 cells was induced by PS nanospheres in a size-dependent manner. Analysis result showed that inhibition of RVD was proportionate to apoptosis rate, correlation coefficient R = 0.9622, and it kept the good linear relationship in a large range. Therefore, the fabricated QCM cytosensor was able to monitor RVD for evaluation of the cytotoxicity of PS nanospheres of different sizes. The study established a convenient QCM cytosensor to evaluate the cytotoxicity of different-sized PS nanospheres, which was expected to provide a tool for evaluation of the cytotoxicity mechanism of PS nanospheres.