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Instrumented NanoPhysiometer for High Throughput Drug Screening. D. Michael Ackermann, Jon Payne, Hilary Samples, James Wells. Labview Front Panel. IMAGE. Big Picture Applications: A Research Tool. Target Population: Protoype of research tool
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Instrumented NanoPhysiometer for High Throughput Drug Screening D. Michael Ackermann, Jon Payne, Hilary Samples, James Wells
Labview Front Panel IMAGE
Big PictureApplications:A Research Tool • Target Population: • Protoype of research tool • Private research of BioMEMS group of VUSE BME dept • Market Demand: • Custom project for specific research • Future implications to broad market High throughput screening Pharmaceutical Testing Toxicology
Motivation Limited study of cell life, activity, and volumes Previous methods: Single phase, stationary state Microliter scale & volumes • Nanophysiometer Nanoliter Scale Real Time Monitoring Decrease: Reagents (if any!) Processing Time 128 Well Plate Assays
Project Goals • Develop nanoliter sized cell culture volume • On-chip pumps for low flow perfusion and drug administration. • Thin film microelectrodes for monitoring of various analytes such as pH, oxygen, glucose and lactose in the media. • Optimize cell culture conditions to maintain cell viability over long periods of time. • Develop a Labview based user interface for mircofluidic control of the NanoPhysiometer
The NanoPhysiometer Goals: 800 um Develop On-Chip Drug Delivery Systems To Achieve Desirable Low Flow Profiles Using Peristaltic Pumping Providing Ideal Parameters for Cell Viability
Physiometer Mask Design Electrodes 800 um Microfluidics Pneumatics
Physiometer Design Concerns • Filter Size • 3 um, 5 um, 8 um • Channel Aspect Ratio • Space between fluidic and pneumatic layers
Fluidics Layer Flexible PDMS Membrane (Valve) [1] S.R. Quake and A. Scherer, "From Micro to Nano Fabrication with Soft Materials", Science 290: 1536-40 (2000). [2] M.A. Unger, H.-P. Chou, T. Thorsen, A. Scherer, and S.R. Quake, "Monolithic Microfabricated Valves and Pumps by Multilayer Soft Lithography", Science 288: 113-116 (2000). Peristaltic Pumps/Valves STATUS: Working! Currently just optimizing.
Electrochemical Monitoring • Use integrated thin film microelectrodes to monitor physiological parameters • pH, glucose, etc. • Electrodes coated with a substrate specific oxidase • Catalyze reaction producing H2O2 • H2O2 then detected STATUS: Will be integrated once fluidics/pneumatics are performing optimally: hard to make!
Optimize Cell Culture Conditions Determine minimal flow rates for maintaining vitality & sufficient perfusion • Allow for physiological measurements • Low flow for detectable pH and electrochemical differential FIBROBLASTS *3-8 mm when spherical, (flat, dendrite-like when attached) *1-2 day doubling time *Robust *Medium- antibiotics, vitamins, essential AA STATUS: We seeded and imaged fibroblast in devices of various sized filters for observation, testing of cell attachment, and minimal survival.
Atmospheric Cell Culture Conditions • Cells demand optimal temperature and CO2/O2 levels • PDMS is gas permeable Plexiglas enclosure • Contained, humidified incubator environment of 5% CO2 Heated Microscope stage • Maintains optimal heated environment of 37 C http://www.cyto.purdue.edu/flowcyt/educate/photos/confocal/images.htm
LabView programming • User control of nanophysiometer system • Program Presets based on experimental needs • Manual Control of Pumps and valves • Measurements & Data acquisition • Show parameter measurements • Time-Lapse Image Capture • Qualitative analysis STATUS: Nearly complete.
Labview Front Panel IMAGE
Schematic Camera LabView Nanophysiometer Electrode Pneumatic Controller D/A Converter
Budget • Mask of device design- $600/mask • PDMS kit - $15 • Cell culture supplies- $300/month • Tubing, wiring, etc.- ~$10 • Electrodes- $500 (owned by lab)
References • Unger, Quake, et. al. Monolithic Microfabricated Valves and Pumps by Multilayer Soft Lithography. Science. Vol. 288. April 7, 2000 • Ho, Chih-Ming. Fluidics – The Link Between Micro and Nano Sciences and Technologies. 0-7803-5998-4/01. 2001 IEEE • Arik, Zurn, et. al. Design, Fabrication and Experimental-Numerical Study of PZT Sensors. MSM 2000. Puerto Rico. • Gonzalez, Moussa. Simulation of MEMS Piezoelectric Micropump for Biomedical Applications. 2002. Algor Incorporated; Technical Document. • Bar-Cohen, Chang. Piezoelectrically Actuated Miniature Peristaltic Pump. March 2000. Proceeding of 2000 SPIE Smart Structures and Materials Symposium. No. 3992-103
Acknowledgements • Dr. Franz Baudenbacher • David Schaffer • Andreas • Nanodelivery, Inc.