A two-compartment microfluidic device for long-term live cell detection based on surface plasmon resonance

Abstract

A two-compartment microfluidic device integrated with a surface plasmon resonance (SPR) interferometric imaging system has been developed for long-term and real-time cell detection. The device uses a porous membrane sandwiched between two chambers to obtain an exact medium exchange rate and minimal fluid shear stress for cell culture. The two-compartment device was optimized by COMSOL simulations and fabricated using Poly (dimethylsiloxane) elastomer replica molding methods. To confirm the capability of the microfluidic device to maintain the cell physiological environment over long intervals, HeLa cells were cultured in the device for up to 48 h. The cell proliferation process was monitored by both SPR and microscopic time-lapse imaging. The SPR response showed four phases with different growth rates, and agreed well with the time-lapse imaging. Furthermore, real-time detection of cell behaviors under different doses of Paclitaxel and Cisplatin was performed. The SPR responses revealed dose-dependent inhibitions of cell proliferation, with distinct drug action kinetics.

FIG. 1.

Distributions of perfusion rate q (a) and shear stress τ (b) in single-compartment and two-compartment culture chambers simulated using COMSOL. Relationship of the average perfusion rate q and shear stress τ with respect to the culture chamber height h (c), the porous membrane thickness d (d), and the porous membrane opening ratio γ (e).

FIG. 2.

Temperature profile of the microfluidic device. The thermal insulation configuration consists of: 1—the medium outlet, 2—the heating ring, and 3—the SPR prism. The two-compartment chamber consists of: 4—the perfusion chamber; 5—porous membrane; and 6—the cell culture chamber. The color indicates the temperature profile; red color indicates high temperature. (a) A common thermal insulation configuration. (b) The optimized thermal insulation configuration for preheating.

FIG. 3.

(a) The schematic illustration of the microfluidic device assembly. (b) The key dimensions of the assembly. (c) The integration of the microfluidic device with the SPR sensor. (d) The photograph of the assembled microfluidic device.

FIG. 4.

Photographs of the SPR imaging system, consisting of the SPR optics system (a), the medium injection system (b), and the temperature controller (c). The variations of temperature (d) and SPR responses to the DMEM (e) in the cell unheated and heated cell culture chamber over 24 h.

FIG. 5.

(a) The SPR sensorgram of HeLa cells growth on the Kretschmann prism bearing 32 nm gold films over 48 h, and the cell confluencies extracted from the microscopic images of HeLa cells at different times. (b) The time-lapse imaging (20×) of HeLa cells grow on a glass substrate bearing 32 nm gold films over 48 h.

FIG. 6.

SPR sensorgrams (a) and MTT test results (b) of HeLa cell growth with the treatment of 1 and 10 μg/ml Paclitaxel and Cisplatin.