Author: Gene Yu Co-Authors: Dr. AlexBlake

Dr. David EddingtonJuly 29, 2010

NSF Research Experiences for Undergraduates (REU) inNovel Advanced Materials and Processing with Applications in Biomedical, Electrical and

Chemical Engineering

ObjectiveDesign 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.

MotivationμBSDs allow in vitro study of:

NeurogenesisSynaptogenesisRegenerationProtein expressionResponses to physical trauma

Image taken fromhttp://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.

RelevanceChemical Delivery

Spatial resolution Current systems affect entire

slice with drug Desire stimulation of specific

areas

Oxygen DeliveryAutomatic Mixing

Saves money Pre-mixing is not required

AutomationMulti-tasking

Image modified fromhttp://www.imagingeconomics.com/issues/articles/MI_2006-08_01.asp

Oxygen Mixing and DeliveryExperimental Set-Up

Y Connector

Output Tube

Valves Gas Feed Lines: 0% and 21%

Oxygen concentration measured by a NeoFox Fiber Optic Oxygen (FOXY) sensor

Oxygen Mixing and DeliveryOutput

Oxygen Mixing and DeliveryGraphical User Interface (GUI)

Delivery CharacterizationμBSD Design

T Channel

Delivery Channel

Reservoir

Delivery CharacterizationExperimental Set-up

μBSD

Valve

DI Water Lines T Channel

Vacuum Line

Delivery CharacterizationNo Tissue Delivery

10ms 15ms 20ms 25ms

2x5ms 3x5ms 4x5ms 5x5ms

Delivery CharacterizationLinear Relationships: No Tissue

Width (µm)

Width (µm)

860

1320

Delivery CharacterizationLinear Relationships: With Tissue

Full Dose Chemical Delivery

Pulsing Dose Chemical DeliveryMaximum Intensities

0 2 4 6Number of 5ms Pulses

Inte

nsi

ty

Inte

nsi

tyIn

ten

sity

Time (min)

Time (min)

2

2

Maximum Intensities

0 10 20

30Valve Open Time (ms)

Inte

nsi

ty

Delivery CharacterizationGUI

ConclusionsOxygen Delivery

Precise and accurate results

Reliable oxygen switching

Chemical Delivery Demonstrated linear

relationship Area of effect: ~2mm x

2mm Selective and

independent valve control

AcknowledgementsFunding

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