EE PhD Oral Examination - Thomas O'Sullivan, Wednesday, June 16, 2010; 10:00am

Stanford University Ph.D. Oral Examination

Title: Implantable fluorescence sensor for continuous molecular monitoring in live animals

Thomas D. O’Sullivan

Department of Electrical Engineering

Research Advisor:  Prof. James S. Harris

Date:  Wednesday, June 16th, 2010

Time: 10:00 am (Refreshments 9:45am)

Location: Clark Center Auditorium (below the patio)

http://campus-map.stanford.edu/index.cfm?ID=07-340

Abstract:

Molecular imaging is an established technique used to visualize and quantify functional information about biological processes in living systems. Specifically, the ability to image fluorescence is a powerful tool considering the wealth of fluorescent probes/proteins that are used in drug discovery and therapeutic evaluation, in studying development and treatment of cancer, in tracking stem cell growth and proliferation in small animals. Fluorescence sensing is also an emerging technique for use in humans.

 

Current approaches to detect fluorescence in vivo rely on devices which use bulky instrumentation, generally requiring anesthetized animal models, and restrict sensing to discrete snapshots in time.  Thus, there is need for continuous, long-term monitoring of fluorescent probes. In this talk, I present our design and fabrication of a miniaturized fluorescence sensor for direct implantation which enable continuous and long-term sensing in freely-moving subjects.

 

The monolithically-integrated, laser-based sensor incorporates the basic optical components of a fluorescence system for sensing Cy5.5 fluorescent dye. I will discuss the materials and microfabrication challenges overcome to achieve the compact integration, as well as the device sensitivity to in vitro and in vivo concentrations of Cy5.5. I will present our efforts and the benefits of using the sensor to monitor the binding kinetics of a molecular probe in cancer tumors and will demonstrate continuous sensing with the sensor implanted in live mice.