Download Three-dimensional microfabricated bioreactor and

Three-dimensional microfabricated
bioreactor and closed-loop control
system
Alex Makowski
Michael Hwang
Jenny Lu
Dr. John Wikswo
Ultimate Project Goals

Computer modulated growth of tissue
structures within microfluidic devices.

Possible uses include drug testing and dose
determination, bypassing several stages of
FDA trials.
Problem Statement- Design progress
is blocked on three distinct fronts:



Sensors are required to provide computer
with necessary information.
Bioreactor design limits the quantity and
quality of cell morphology within the device.
Previously used cells (primary human
fibroblasts) do not easily form tissue-like
structures.
Subsequent Requirements:



Choose or design an appropriate sensor for
pH measurements (most needed to
determine cell metabolism and health).
Choose a cell line that will exhibit some kind
of morphological change under successful
conditions.
Redesign the bioreactor to incorporate new
cell line and maximize efficiency of pH
sensors.
Previous cell lines used…

Primary human fibroblast and endothelial
cells




High cost
Lower passages
Difficult to exhibit 3D morphology
Need morphology as control
Why use MCF10A cell line?

Human breast epithelial
cell line (MCF10A)



Have in stock
Less expensive
Forms acinar
morphology
Illustration courtesy of Weaver Lab
Cell Culture Model of Epithelial Acini
Confocal Imaging of Acini
from 3-D matrigel cultures
Illustration courtesy of Cassio Lynm, JAMA
Simplified Experimental Setup
Electrical connection for tubular Ti electrode
Copper plate
Copper wire
Titanium tube
Slide Courtesy of Sayed A. M. Marzouk
United Arab Emirates University
Electroplating the inner wall of Ti tube with IrO2
Tygon tube
To potentiostat
Pt tube
(counter electrode)
Electroplating solution
Titanium tube to be
coated
Pt tube
(counter electrode)
(Working electrode)
pump
Slide Courtesy of Sayed A. M. Marzouk
United Arab Emirates University
Improvements over pH Optical
fiber-type sensor
• Improved response time (6 s vs. 2-3
min.)
– Important for frequent
measurements
– Allows faster recalibration
• No stagnant volume
– T-junction for fiber creates a volume
around sensor with little or no
convective flow
– Lack of convection  diffusionlimited analyte transport  even
longer response time