Culture of insect cells contracting spontaneously; research moving toward an environmentally robust hybrid robotic system.

Here we propose an environmentally robust hybrid (biotic-abiotic) robotic system that uses insect heart cells. Our group has already presented a hybrid actuator using rat heart muscle cells, but it is difficult to keep rat heart muscle cells contracting spontaneously without maintaining the culture conditions carefully. Insect cells, by contrast, are robust over a range of culture conditions (temperature, osmotic pressure and pH) compared to mammalian cells. Therefore, a hybrid robotic system using not mammalian cells but insect cells can be driven without precise environmental control. As a first step toward the realization of this robotic system, the larvae of two lepidopteran species, Bombyx mori (BM) and Thysanoplusia intermixta (TI) were excised and the culture conditions of their dorsal vessel (insect heart) cells were examined. As a result, spontaneously contracting TI cells derived from the dorsal vessel were obtained. The contraction of TI cells started on the 7th day and continued for more than 18 days. Spontaneously contracting BM cells were not obtained in this study. These experimental results suggest the possibility of constructing an environmentally robust hybrid robotic system with living cells in the near future.