Three-dimensional microfabricated bioreactor and closed-loop control

system

Alex MakowskiMichael HwangJenny 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 Acinifrom 3-D matrigel cultures

Illustration courtesy of Cassio Lynm, JAMA

Simplified Experimental Setup

Titanium tube

Copper plateCopper wire

Electrical connection for tubular Ti electrode

Slide Courtesy of Sayed A. M. Marzouk

United Arab Emirates University

Electroplating the inner wall of Ti tube with IrO2

Titanium tube to be coated

)Working electrode(

Pt tube

(counter electrode)

Pt tube

)counter electrode(

To potentiostat

pumpElectroplating solution

Tygon tube

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 diffusion-limited analyte transport even longer response time