Maciej Grajewski, Gert IJ. Salentijn, Ruby E.H. Karsten, Peter Olinga and Elisabeth Veropoorte
uTAS 2018 and SLAS 2019
Development of a system for monitoring cholestasis development in precision-cut liver slices (PCLS) an ex-vivo tissue model for studying drug toxicity.
Real-time monitoring of biliary transport in precision-cut liver slices
Saraí M. Torres Delgado, Jan G. Korvink, Dario Mager,*
In this paper we present a comprehensive description of the design, fabrication and operation of an electrified Lab-on-a-Disc (eLoaD) system. The smart platform is developed to extend conventional Lab-on-a-Disc applications with an electronic interface, providing additional flow control and sensing capabilities to centrifugal microfluidics platforms. Wireless power is transferred from a Qi-compliant transmitter to the eLoaD platform during rotation. An Arduino-based microcontroller, a Bluetooth communication module, and an on-board SD-card are integrated into the platform. This generalises the applicability of the eLoaD and its modules for performing a wide range of laboratory unit operations, procedures, or diagnostic assays, all controlled wirelessly during spinning. The lightweight platform is fully reusable and modular in design and construction. An interchangeable and non-disposable application disc is fitted with the necessary sensors and/or actuators for a specific assay or experiment to be performed. A particular advantage is the ability to continuously monitor and interact with LoaD experiments, overcoming the limitations of stroboscopy. We demonstrate the applicability of the platform for three sensing experiments involving optical, electrochemical, and temperature detection, and one actuation experiment involving controlled heating/cooling. The complete electronic designs and example programming codes are extensively documented in the supplementary material for easy adaptation.
William Hale, Gabriel Rossetto, Rachael Greenhalgh, Graeme Finch and Marcel Utz*
Lab Chip, 2018,18, 3018-3024
A generic approach is presented that allows high-resolution NMR spectroscopy of water/oil droplet emulsions in microfluidic devices. Microfluidic NMR spectroscopy has recently made significant advances due to the design of micro-detector systems and their successful integration with microfluidic devices. Obtaining NMR spectra of droplet suspensions, however, is complicated by the inevitable differences in magnetic susceptibility between the chip material, the continuous phase, and the droplet phases. This leads to broadening of the NMR resonance lines and results in loss of spectral resolution. We have mitigated the susceptibility difference between the continuous (oil) phase and the chip material by incorporating appropriately designed air-filled structures into the chip. The susceptibilities of the continuous and droplet (aqueous) phases have been matched by doping the droplet phase with a Eu3+ complex. Our results demonstrate that this leads to a proton line width in the droplet phase of about 3 Hz, enabling high-resolution NMR techniques.
Saraí M. Torres Delgado, David J. Kinahan, Lourdes Albina Nirupa Julius, Adam Mallette, David Sáenz Ardila, Rohit Mishra, Celina M. Miyazaki, Jan G. Korvink, Jens Ducrée, Dario Mager
Biosensors and Bioelectronics, 2019
In this paper we present a
wirelessly powered array of 128 centrifugo-pneumatic valves that can be
thermally actuated on demand during spinning. The valves can either be
triggered by a predefined protocol, wireless signal transmission via Bluetooth, or in response to a sensor monitoring a parameter like the temperature, or homogeneity of the dispersion. Upon activation of a resistive
heater, a low-melting membrane (Parafilm™) is removed to vent an
entrapped gas pocket, thus letting the incoming liquid wet an
intermediate dissolvable film and thereby open the valve. The proposed
system allows up to 12 heaters to be activated in parallel, with a
response time below 3 s, potentially resulting in 128 actuated valves in
under 30 s. We demonstrate, with three examples of common and standard
procedures, how the proposed technology could become a powerful tool for
implementing diagnostic assays on Lab-on-a-Disc. First, we implement
of 64 valves during rotation in a freely programmable sequence, or upon
user input in real time. Then, we show a closed-loop centrifugal flow
control sequence for which the state of mixing of reagents, evaluated
from stroboscopically recorded images, triggers the opening of the valves. In our last experiment, valving and closed-loop control are used to facilitate centrifugal processing of whole blood.
Ruby E.H. Karsten. Maciej Grajewski, Gert IJ. Salentijn, Viktoriia Starokozkho, Elisabeth Verpoorte, Peter Olinga
University of Groningen
Develop a disease model to study drug-induced cholestasis in precision-cut liver slices (PCLS) in real time
Murine precision-cut liver slices as a disease model to predict drug-induced cholestasis