Label-Free Quartz Crystal Microbalance with Dissipation Monitoring of Resveratrol Effect on Mechanical Changes and Folate Receptor Expression Levels of Living MCF‑7 Cells: A Model for Screening of Drugs

Quartz crystal microbalance with dissipation (QCM-D) monitoring was used for real-time and label-free detection of changes and folate receptor (FR) expression levels on living MCF-7 cells for evaluating the anticancer activity of resveratrol. Here, the mechanical changes of cellular responses to resveratrol were tracked by a poly­(l-lysine) (PLL) modified QCM-D sensor, and the inhibition effect of resveratrol on FR expression levels on MCF-7 cells was monitored by chitosan-folic acid (CS-FA) composite membrane functionalized Au substrate for the first time. Changes in morphology and the cellular state of MCF-7 cells stimulated by resveratrol at different concentrations were detected by inverted fluorescence microscopy and flow cytometry. Atomic force microscopy confirmed that resveratrol influenced the cellular mechanical properties. The results indicated that the MCF-7 cells lose their original elasticity and increase their stiffness induced by resveratrol. It was further observed by confocal fluorescence imaging that resveratrol reduced the FR expression levels on the living cells surface. This study established a typical model of the QCM-D biosensor to evaluate the protein biomarker expression levels on the cells surface. QCM-D, which was used to investigate potential targets for an antitumor drug on living cells and realize a better understanding of the drug action mechanism, was expected to be developed into a promising tool for the screening of drugs