|An automated modular microsystem for enzymatic digestion with gut-on-a-chip applications
Haan, P. de; Ianovska, M.A. ; Mathwig, K. ; Bouwmeester, H. ; Verpoorte, E. - \ 2020
In: 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2017. - Chemical and Biological Microsystems Society (21st International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2017 ) - ISBN 9780692941836 - p. 1593 - 1594.
Digestion - Enzyme kinetics - Gut-on-a-chip - Organ-on-a-chip
Gut-on-a-chip models have gained attention as replacements for other cell-based assays or animal studies in drug development or toxicological studies. These models aim to provide a more accurate representation of the in vivo situation in form and function; however, no digestive processes have been included in these systems so far. This work describes a miniaturized digestive system based on artificial digestive juices that digest liquid samples in a series of three microreactors. After optimization of the pH value of juices and mixtures, samples leading to fluorescent products were digested to demonstrate enzyme functionality and to determine kinetic parameters.
Digestion-on-a-chip: A continuous-flow modular microsystem recreating enzymatic digestion in the gastrointestinal tract
Haan, Pim De; Ianovska, Margaryta A. ; Mathwig, Klaus ; Lieshout, Glenn A.A. Van; Triantis, Vassilis ; Bouwmeester, Hans ; Verpoorte, Elisabeth - \ 2019
Lab on a Chip 19 (2019)9. - ISSN 1473-0197 - p. 1599 - 1609.
In vitro digestions are essential for determining the bioavailability of compounds, such as nutrients. We have developed a cell-free, miniaturized enzymatic digestive system, employing three micromixers connected in series to mimic the digestive functions of the mouth, stomach and small intestine. This system continuously processes samples, e.g. containing nutrients, to provide a constant flow of digested materials which may be presented to a subsequent gut-on-a-chip absorption module, containing living human intestinal cells. Our system incorporates three-compartment enzymatic digestion, one of the key functions of the gastrointestinal tract. In each of these compartments, we modify the chemical environment, including pH, buffer, and mineral composition, to closely mimic the local physiological environment and create optimal conditions for digestive processes to take place. It will therefore provide an excellent addition to existing gut-on-a-chip systems, providing the next step in determining the bio-availability of orally administered compounds in a fast and continuous-flow ex vivo system. In this paper, we demonstrate enzymatic digestion in each separate compartment using compounds, starch and casein, as model nutrients. The use of transparent, microfluidic micromixers based on chaotic advection, which can be probed directly with a microscope, enabled enzyme kinetics to be monitored from the very start of a reaction. Furthermore, we have digested lactoferrin in our system, demonstrating complete digestion of this milk protein in much shorter times than achievable with standard in vitro digestions using batch reactors.
High-throughput, non-equilibrium studies of single biomolecules using glass-made nanofluidic devices
Fontana, Mattia ; Fijen, Carel ; Lemay, Serge G. ; Mathwig, Klaus ; Hohlbein, Johannes - \ 2019
Lab on a Chip 19 (2019)1. - ISSN 1473-0197 - p. 79 - 86.
Single-molecule detection schemes offer powerful means to overcome static and dynamic heterogeneity inherent to complex samples. However, probing biomolecular interactions and reactions with high throughput and time resolution remains challenging, often requiring surface-immobilized entities. Here, we introduce glass-made nanofluidic devices for the high-throughput detection of freely-diffusing single biomolecules by camera-based fluorescence microscopy. Nanochannels of 200 nm height and a width of several micrometers confine the movement of biomolecules. Using pressure-driven flow through an array of parallel nanochannels and by tracking the movement of fluorescently labelled DNA oligonucleotides, we observe conformational changes with high throughput. In a device geometry featuring a T-shaped junction of nanochannels, we drive steady-state non-equilibrium conditions by continuously mixing reactants and triggering chemical reactions. We use the device to probe the conformational equilibrium of a DNA hairpin as well as to continuously observe DNA synthesis in real time. Our platform offers a straightforward and robust method for studying reaction kinetics at the single-molecule level.
Nanofluidic device, fluidic system and method for performing a test
Hohlbein, J.C. ; Mathwig, Klaus - \ 2018
Octrooinummer: WO2018060263, gepubliceerd: 2018-04-05.
Proposed is a nanofluidic device (20) comprising a first microchannel (31 ), a first branch nanochannel (33) branching off the first microchannel (31 ), a second microchannel (32), a second branch nanochannel (34) branching off the second microchannel (32), and a mixing nanochannel (36). The mixing nanochannel hydraulic resistance is at least one thousand times larger than each of the first and second microchannel hydraulic resistance. A junction (35) is provided which connects the first branch channel, the second branch channel and the mixing nanochannel. The junction (35): - receives a first laminar fluid flow from the first branch nanochannel (33) and a second laminar fluid flow from the second branch nanochannel (34), and - contacts the first and second laminar fluid flows with each other to establish diffusion mixing of the first and second fluids, and - discharge the mixed first and second fluids into the mixing nanochannel inlet (36a).
A Nanofluidic Mixing Device for High-throughput Fluorescence Sensing of Single Molecules
Mathwig, Klaus ; Fijen, C. ; Fontana, M. ; Lemay, S.G. ; Hohlbein, J.C. - \ 2017
Procedia Technology 27 (2017). - ISSN 2212-0173 - p. 141 - 142.
We introduce a nanofluidic mixing device entirely fabricated in glass for the fluorescence detection of single molecules. The design consists of a nanochannel T-junction and allows the continuous monitoring of chemical or enzymatic reactions of analytes as they arrive from two independent inlets. The fluorescently labeled molecules are tracked before, during and after they enter the mixing region, and their reactions with each other are observed by means of optical readout such as Förster Resonance Energy Transfer (FRET). Our method can be used for analyzing the kinetics of DNA annealing in a high-parallelized fashion.