The Directional Freezing Effects on Biological Cells in a Microfluidic Cell Culture System

Cryotherapy is a prospective also green method for malignant tumor treatment. At low temperature, the cell viability relates with the cooling rate, temperature threshold, freezing interface as well as ice formation. In this paper a series of directional freezing processes and cell responses in a culture microchip were experimentally investigated. The temperature in the microchip was manipulated by a thermoelectric cooler. The surviving cells, necrotic and apoptotic cells under different cryotreatment (duration of the freezing process, freeze-thaw cycle, post-culture et al) were stained and distinguished by PI and FITC-Annexin V. The locations of the ice front and cell death boundary were observed and recorded through an inverted microscopy. By controlling the cooling process in a microfluidic channel, it is possible to recreate a sketch of biological effect during the process of simulated cryosurgery.