Investigation of scaffold materials for a bio-micropump using IPS cell derived cardiomyocytes

Recently, various micropumps have been developed, however, they fundamentally depends on external energy such as electricity. Thus, there is a limitation of integration into devices. We previously developed bio-micropumps exploiting contractile forces of cardiomyocytes utilizing glucose in the medium as chemical energy. However, one fatal issue is that they need primary cardiomyocytes as actuators, which are ethically inadequate due to animal sacrifice. On the other hand, induced pluripotent stem (iPS) cells proliferate indefinitely and can be differentiated into a number of cell types, including cardiomyocytes. We thought that the above issues can be addressed by utilizing iPS cells. To realize this, a prototype system to pump fluid by differentiated cardiomyocytes from iPS was developed. To create this device, a scaffold material and its structure to transmit cellular contractile force to fluid in a microchannel is critically important. We here utilized 2 popular materials (glass and polydimethylsiloxane (PDMS)) which were mounted on a microchip as a tent-like shape and compared regarding attachment and movement of fluid in a microchannel. The microchips were irradiated with O₂ plasma and coated with gelatin, and mouse-derived iPS cells were seeded on the microchip and differentiated into cardiomyocytes. Ultra thin glass has a better attachment property than PDMS, however, the fluid oscillation was not observed. On the other hand, thin PDMS membrane showed fluid oscillations although the attachment rate was not as good as glass. These fundamental knowledge is useful for designing cell-based bio-microdevices.