150 likes | 313 Vues
Localized and automated chemical and oxygen delivery system for microfluidic brain slice devices. Author: Gene Yu Co-Authors: Dr. AlexBlake Dr. David Eddington July 29, 2010 NSF Research Experiences for Undergraduates (REU) in
E N D
Localized and automated chemical and oxygen delivery system for microfluidic brain slice devices Author: Gene Yu Co-Authors: Dr. AlexBlake Dr. David Eddington July 29, 2010 NSF Research Experiences for Undergraduates (REU) in Novel Advanced Materials and Processing with Applications in Biomedical, Electrical and Chemical Engineering
Objective • Design localized and automated delivery system for microfluidic brain slice devices (μBSDs) • Delivers chemicals/drugs and gases • Automatically mixes oxygen • Characterize delivery of chemicals through tissue Image taken from Mohammed, J, Caicedo, H, Fall, C, & Eddington, D. (2008). Microfluidic add-on for standard electrophysiology chambers. Lab Chip, 8, 1048-1055.
Motivation • μBSDs allow in vitro study of: • Neurogenesis • Synaptogenesis • Regeneration • Protein expression • Responses to physical trauma Image taken from http://www.koki.hu/cdnb/research/research.html Rambani, K, Vukasinovic, J, Glezer, A, & Potter, S. (2009). Culturing thick brain slices: an interstitial 3d microperfusion system for enhanced viability. Journal of Neuroscience Methods, 180, 243-254.
Relevance • Chemical Delivery • Spatial resolution • Current systems affect entire slice with drug • Desire stimulation of specific areas • Oxygen Delivery • Automatic Mixing • Saves money • Pre-mixing is not required • Automation • Multi-tasking Image modified fromhttp://www.imagingeconomics.com/issues/articles/MI_2006-08_01.asp
Oxygen Mixing and DeliveryExperimental Set-Up • Oxygen concentration measured by a NeoFox Fiber Optic Oxygen (FOXY) sensor Valves Gas Feed Lines: 0% and 21% Y Connector Output Tube
Delivery CharacterizationμBSD Design Reservoir T Channel Delivery Channel
Delivery CharacterizationExperimental Set-up DI Water Lines T Channel Valve μBSD Vacuum Line
Delivery CharacterizationNo Tissue Delivery 10ms 15ms 20ms 25ms 2x5ms 3x5ms 4x5ms 5x5ms
Delivery CharacterizationLinear Relationships: No Tissue 860 Width (µm) 1320 Width (µm)
Delivery CharacterizationLinear Relationships: With Tissue Full Dose Chemical Delivery Maximum Intensities Intensity Intensity 4 2 0 2 6 Time (min) Number of 5ms Pulses Pulsing Dose Chemical Delivery Maximum Intensities Intensity Intensity 30 20 2 0 10 Time (min) Valve Open Time (ms)
Conclusions • Oxygen Delivery • Precise and accurate results • Reliable oxygen switching • Chemical Delivery • Demonstrated linear relationship • Area of effect: ~2mm x 2mm • Selective and independent valve control
Acknowledgements • Funding • NSF-REU • DoD-ASSURE • EEC-NSF Grant # 0755115 • REU Directors • Christos G. Takoudis, Ph.D. • Greg Jursich, Ph.D. • Research Advisor • David Thomas Eddington, Ph.D. • Mentors • Alexander Blake, Ph.D. • Gerardo Mauleon