Intracellular Calcium Increases Due to Curcumin Measured Using a Single-Cell Biochip

Abstract

Here is reported a microfluidic single-cell method for real-time monitoring of the effects of curcumin on the calcium change in a single glioma cell. The method is based on the quantitative measurement of intracellular calcium concentrations in the cell retained using a glass biochip. The single-cell biochip consisted of three reservoirs, three channels, and a chamber containing a V-shaped structure for single-cell selection and retention. The design of the cell retention structure, and on-chip dye loading helped to minimize the damage to fragile cells that occurs in conventional calcium measurement methods. Curcumin, which is a herbal ingredient from Curcuma longa, has been shown to cause an increase in intracellular calcium in a single glioma cell (U-87 MG). Different concentrations of curcumin (5 and 10 µM) were investigated for their abilities to stimulate sustained elevations of the intracellular calcium concentrations in the single cell. Ionomycin was used as a control to saturate intracellular calcium needed for concentration calibration. The microfluidic chip measures intracellular calcium changes in real time, needs only a small number of cells, requires low quantities of reagents, and minimizes cell damage by the use of on-chip dye loading and reagent treatment.