Development of a biochip with serially connected pneumatic balloons for cell-stretching culture

The stretch stimulus is one of the most important mechanical stimuli sensed by cells. In the present study, a simple microdevice was developed to study the effects of the application of different strain magnitudes to cells. The pressure drop effect in a microchannel was utilized to generate a wide range of strain magnitudes in a single device. The microdevice consisted of 2 layers of polydimethylsiloxane (PDMS), and no alignment process was needed to fabricate it. Eight serially connected balloon structures were included in the device. Cells cultured on the surface of the balloons were stretched by inflating the balloons pneumatically. Finite element analysis (FEA) revealed that 8 different balloons in a single device could generate strains of 14.3–7.7% when air pressure was applied at 50 kPa to the air inlet. Cell culture experiments confirmed the useful application of a wide range of strain magnitudes to cells cultured on balloons inflated to different degrees. The new microdevice utilizing the pressure drop effect is a convenient instrument for the study of cellular mechanotransduction.