Faculty Candidate Seminar
Catch me if you can – BioMems Devices to Capture and analyze rare circulating tumor cells for cancer Diagnostics
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Cancer causes about 13% of all global deaths in 2007. Among these, metastasized tumors are responsible for over 90% of the mortality. Circulating tumor cells (CTC) are tumor cells in bloodstream during the metastasis process. Sensitive detection of CTC in a minimally invasive and user-friendly manner will revolutionize the clinical management of caner patients. The current CTC capture and identification has significant barriers including the rareness of the CTC (1 out of 10 billion blood cells), multiple procedural steps, handling of relatively large volumes of blood, substantial human intervention, extremely high cost, and the lack of reliability for the detection methods.
I will introduce the development of a novel micro filtration technology for capturing CTC from human peripheral blood. 90% capture efficiency and 107 enrichment are demonstrated in the model system using cultured cancer cells admixed in blood. Testing results from the model system and clinical results from cancer patient samples show significantly improvements of this technology over the only FDA approved commercial system. Pathological analysis by immunohistochemical staining, genetic analysis by cell electrolysis and PCR/RT-PCR, genomic analysis by laser microdissection and comparative genomic hybridization, can be performed directly on the devices. The more recent 3D microfiltration devices are capable of capturing viable CTCs and culture them for at least two weeks. The novel microdevice based CTC enrichment technology will provide a cost effective method for CTC monitoring with higher capture efficiency, higher enrichment, faster processing time and more reliable results, which can benefit both the cancer clinic and basic cancer research.
Siyang Zheng received his B.S. degree in Biological Sciences and Biotechnologies from Tsinghua University, Beijing, China, in 1996. He received his M.S. in Electrical Engineering from the Pennsylvania State University, University Park, PA, U.S.A., in 2000. He worked at Lucent Technology, Holmdel, NJ, U.S.A. for one year before he joined the Micromachining group in at California Institute of Technology (Caltech), Pasadena, CA, U.S.A. as a graduate student in 2002. He obtained his Ph.D. in Electrical Engineering from Caltech in 2007 under the guidance of Dr. Yu-Chong Tai and is currently working as a postdoctoral scholar in the same laboratory. His broad research experiences covered lab-on-a-chip system for cell separation and analysis, electrical impedance sensing, laser-induced fluorescence detection, MEMS sensors/actuators, micro/nano fabrication, on-chip molecular self-assembly, microfluidic integration technology.