A spherical micropump actuated by cultured cardiomyocytes

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A spherical micropump actuated by cultured
cardiomyocytes
Teacher Cheng-Hsien Liu Student Chien-Yu
Chen(???) Date 05/16/2007
Reference FABRICATION OF PREMITIVE SPHERICAL
MICROPUMP POWERED BY
CARDIOMYOCYTESMICRO SHERICAL HEART, µTAS2006,
p.1133-1135
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Outline

• Introduction
• Design concept fabrication setup
• Experiment result
• Conclusion

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Introduction

• Efficient biochemical devices incorporating cells
  into a miniaturized mechanical system have been
  frequently reported.
• Biochemical reactors or analysis systems
  exploiting cellular biochemical functions are the
  mainstream.

Schematic view
Cross-sectional view along line AB
Design of a bio-actuated pump on a microchip
powered by a cultured cardiomyocyte sheet.
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Design concept
Design of a micro spherical heart. A
cardiomyocyte sheet covers the hollow sphere
entirely.
Schematic view Cross-sectional view along line
A-B.
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Fabrication setup

• Threading a capillary through a hole
• on a sugar ball, and applying melted
• glucose around the hole to prevent
• penetration of PDMS prepolymer.

(C) Drawing and insertion of capillaries
to make them be into the sphere partly
and attachment of them to the sphere by
glue.
(B)PDMS dispense and solidification
while rotating above a hotplate at 100ºC.
(D) Dissolving the sugar ball by water.
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Experiment result
A fabricated PDMS hollow sphere
before transplantation of a cardiomyocyte
sheet. (About 5 mm in diameter, 250 µm in
thickness)
A hollow sphere immersed in medium
after transplantation of a cardiomyocyte sheet.
1. Washed with ethanol. 2. Sterilized using UV
light for 15 min. 3. Immersed for fibronectin
(from bovine serum, Sigma) solution in
phosphate buffered saline (PBS) to promote
cardiomyocyte attachment.
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Experiment result
Schematic view describing the observation method
and a measured parameter (x).
Displacement time-course of one particle near the
center of the capillary for 5 s at 37C. Gray and
black plots indicate particle displacement before
and after cardiomyocyte sheet transplantation, res
pectively.
Fluid oscillating frequency 0.4 Hz Maximum
displacement 70 µm
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Conclusion

• Regular fluid motion in a capillary connected to
  the hollow pumping sphere wrapped a beating
  cardiomyocyte sheet was confirmed, with the
  device working continuously over 5 days.
• This bio/artificial hybrid fluidic device is a
  fully integrated, wireless mechanochemical
  converter, exploiting a spherical heart-like
  pumping structure.
• Pumping action is driven with only chemical
  energy input from culture milieu without any
  requirement for coupled external energy sources,
  unlike conventional actuators.
• Critical issue to discuss How to control the
  flow rate ?

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• Thank you !

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Other references

• 1. Y. Tanaka, K. Morishima, T. Shimizu, A.
  Kikuchi, M. Yamato, T. Okano, T. Kitamori, Lab
  Chip, 6, 362-368, (2006).
• 2. T. Shimizu, M. Yamato, Y. Isoi, T. Akutsu, T.
  Setomaru, K. Abe, A. Kikuchi, M. Umezu, T. Okano,
  Circ. Res., 90, e40-e48, (2002).