Periodic Reporting for period 1 - CAPTURE-CTC (A Streptavidin Microarray Platform for Capturing of Circulating Tumor Cells from the Blood of Cancer Patients)
Reporting period: 2015-06-01 to 2016-11-30
During the first ERC PoC grant CAPTURE-CTC the following milestones relevant for the future validation and commercialization of the CTC chip planned in this project were achieved:
Generation of a Micropatterned Microfluidic Capture Chip and Proof of its Capturing Capability: The capture principal of the micropatterned microfluidic chip has been successfully developed. The chip manufacturing procedure has been optimized to ensure a reliable and reproducible “production” of chips for all required tests in the course of the project and tested the developed cell capture principal with viable breast cancer cell line cells sensitized with biotinylated antibodies. Following cell immobilization, the flat surface of the glass slide allows for extraction of cells of interest by micromanipulation, while keeping cell morphology intact as crucial prerequisite for further characterization.
Improvement of Micropatterned Microfluidic Capture Chip Structure and Performance: The modular setup of the chip-manufacturing readily allows alterations in chip architecture, making it a very versatile platform. Multiple structural parameters were modified and compared in respect to cell-capture efficiency to elucidate an optimal Capture-CTC chip design. Conclusively, we determined an ideal chip structure consisting of a 50 µm streptavidin pattern combined with a herringbone chamber ceiling (125 µm total height, 100 x 50 x 75 groove dimensions) yielding cell recoveries of up to 96 %.
Capture of cancer cells in spiked blood samples from healthy donors: CTCs are extremely rare within a high background of healthy blood cells (1 CTC in 108 - 109 blood cells). An additional pre-enrichment of the tumor cell fraction is necessary to ensure specific and sensitive cell capture and prevent clogging of the microfluidic device as well as excess cell background. The Parsortix™ system (ANGLE plc) is a size-based, label-free, pre-enrichment platform that has been intensively tested at the UKE. First proof-of-principle studies on patient blood samples demonstrated the feasibility of our new system in a clinical setting.
Taken together, the improved version of this chip is now ready for clinical testing. Moreover, we have submitted a patent application to protect the IP and made promising contacts to industry partners for future commercialization of the chip platform. The successful development of CTC profiling technologies for therapeutic targets and resistance mechanisms as well as the establishment of cell culture conditions for CTCs has furthermore enabled us now to implement short-term CTC cultures for future drug testing purposes.