Biological contractile regulation of micropillar actuator driven by insect dorsal vessel tissue

This paper examines biological regulation of micropillar actuation by insect dorsal vessel tissue. Micromechanical devices using mammalian cardiomyocytes have been reported, but they work only at only at 37degC and at pH of around 7.4. On the other hand, insect cells can survive and proliferate at 20 to 30degC and at pH 6 to 8. We have already proposed utilization of insect heart tissue as a bio-actuator and demonstrated a micropillar actuator. For practical use, a regulation technique should be developed. It was reported that two neuropeptides, proctolin and crustacean cardioactive peptide CCAP could accelerate heart beat. In this study, addition of CCAP at 10^-6 M accelerated the frequency of the micropillar actuation 5.6-fold from 0.11 to 0.62 Hz and it returned to nearly the original value in 5 min. Proctolin addition up to 10^-5 M had little effect on the actuation. These results showed that CCAP is useful in frequency regulation of a bio-actuator driven by dorsal vessel tissue.