Threedimensional microfabricated bioreactor and closedloop control system Alex

Three-dimensional microfabricated bioreactor and closed-loop control system Alex Makowski Michael Hwang Jenny Lu Dr. John Wikswo

Ultimate Project Goals l Computer modulated growth of tissue structures within microfluidic devices. l Possible uses include drug testing and dose determination, bypassing several stages of FDA trials.

Problem Statement- Design progress is blocked on three distinct fronts: l l l 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: l l l Choose or design an appropriate sensor for p. H 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 p. H sensors.

Previous cell lines used… l Primary human fibroblast and endothelial cells l l High cost Lower passages Difficult to exhibit 3 D morphology Need morphology as control

Why use MCF 10 A cell line? l Human breast epithelial cell line (MCF 10 A) l l l 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 Ir. O 2 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 p. H 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