Andreas Hierlemann


Last Name

Hierlemann

First Name

Andreas

ORCID

0000-0002-3838-2468

Organisational unit

03684 - Hierlemann, Andreas / Hierlemann, Andreas

Search Results

Publications1 - 10 of 414
  • A microfluidic single-cell array for in situ laminar-flow-based comparative culturing of budding yeast cells
    Item type: Journal Article
    Zhu, Zhen; Wang, Yingying; Peng, Ruobo; et al. (2021)
    Talanta
    To facilitate in situ comparative culturing of budding yeast cells in a precisely controlled microenvironment, we developed a microfluidic single-cell array (MiSCA) with 96 traps (16 rows × 6 columns) for single-cell immobilization. Through optimization of the distances between neighboring traps and the applied flow rates by using a hydraulic equivalent circuit of the fluidic network, yeast cells were delivered to each column of the array by laminar focused flows and reliably captured at the traps by hydrodynamic forces with about 90% efficiency of cell immobilization. Immobilized cells in different columns within the same device can then be cultured in parallel while being exposed to different media and compounds delivered by laminar flows. For biological validation of the comparative cell-culturing device, we used budding yeast that can express yellow fluorescent protein upon the addition of β-estradiol in cell-culturing medium. Experimental results show successful induction of fluorescence in cells immobilized in desired columns that have been dosed with β-estradiol. The MiSCA system allows for performing sets of experiments and control experiments in parallel in the same device, or for executing comparative experiments under well-defined laminar-perfusion conditions with different media, as well as in situ monitoring of dynamic cellular responses upon different analytical compounds or reagents for single-cell analysis.
  • Transwell-Based Microfluidic Platform for High-Resolution Imaging of Airway Tissues
    Item type: Journal Article
    Kurmashev, Amanzhol; Boos, Julia A.; Laventie, Benoît-Joseph; et al. (2024)
    Advanced Materials Technologies
    Transwell-based airway models have become increasingly important in studying the effects of respiratory diseases and drug treatment at the air-liquid interface of the lung epithelial barrier. However, the underlying mechanisms at the tissue and cell level often remain unclear, as transwell inserts feature limited live-cell imaging compatibility. Here, a novel microfluidic platform is reported for the cultivation of transwell-based lung tissues providing the possibility to alternate between air-liquid and liquid-liquid interfaces. While the air-liquid interface recapitulates physiological conditions for the lung model, the liquid-liquid interface enables live imaging of the tissue at high spatiotemporal resolution. The plastics-based microfluidic platform enables the insertion and recuperation of the transwell inserts, which allows for tissue cultivation and analysis under standardized well plate conditions. The device is used to monitor infections of Pseudomonas aeruginosa in human stem-cell-derived bronchial epithelial tissue. The progression of a P. aeruginosa infection in real-time at high resolution is continuously imaged, which provides insights into bacterial spreading and invasion on the apical tissue surface, as well as insights into tissue breaching and destruction over time. The airway tissue culture system is a powerful tool to visualize and elucidate key processes of developing respiratory diseases and to facilitate drug testing and development.
  • Multiple Single-Unit Long-Term Tracking on Organotypic Hippocampal Slices Using High-Density Microelectrode Arrays
    Item type: Journal Article
    Gong, Wei; Senčar, Jure; Bakkum, Douglas J.; et al. (2016)
    Frontiers in Neuroscience
    A novel system to cultivate and record from organotypic brain slices directly on high-density microelectrode arrays (HD-MEA) was developed. This system allows for continuous recording of electrical activity of specific individual neurons at high spatial resolution while monitoring at the same time, neuronal network activity. For the first time, the electrical activity patterns of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied during several consecutive weeks at daily intervals. An unsupervised iterative spike-sorting algorithm, based on PCA and k-means clustering, was developed to assign the activities to the single units. Spike-triggered average extracellular waveforms of an action potential recorded across neighboring electrodes, termed “footprints” of single-units were generated and tracked over weeks. The developed system offers the potential to study chronic impacts of drugs or genetic modifications on individual neurons in slice preparations over extended times.
  • Tubing-free Microfluidic Platform for Co-culture of 2D Adherent Cells and 3D Microtissue Spheroids
    Item type: Other Conference Item
    Gökçe, Furkan; Hierlemann, Andreas; Modena, Mario M. (2019)
    23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2019)
    We present a tubing-free, standard 384-well-format-based microfluidic platform to co-culture 2D adherent cells and 3D microtissue spheroids, while they are fluidically interconnected. The culture wells of the platform are separated by capillary stop valves and can be selectively treated to promote or to prevent adhesion of cells and/or microtissue spheroids. The wells can be interconnected after surface treatment by simply filling the reservoirs with culture medium so that the interaction between the different cell populations can be investigated.
  • Microphysiological model of the placental barrier to study human Brucella infections and antibiotic treatment during pregnancy
    Item type: Presentation
    Chaliotis, Odysseas; Boos, Julia; Dehio, Christoph; et al. (2023)
  • 32-Channel Integrated Electrical Impedance Sensors on a Multi-Functional Neural Microelectrode Array Platform
    Item type: Conference Paper
    Viswam, Vijay; Bounik, Raziyeh; Shadmani, Amir; et al. (2016)
    Procedia Engineering ~ Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016
    An integrated measurement platform was implemented to make in-vitro impedance measurements of neuronal cells on a multi-functional CMOS microelectrode array (MEA). This high-density array is made of 59’760 platinum microelectrodes with a pitch of 13.5μm. Impedance sensing can be performed through 32 electrodes in parallel, while the electrode sites can be arbitrarily chosen on the array. A wave generator was also integrated on chip to perform impedance spectroscopy within a wide frequency range from 1Hz to 1MHz. For a proof of concept, we show the magnitude and phase plots of platinum electrode-electrolyte interface impedances for different electrode sizes at different frequency ranges.
  • Automatic spike sorting evaluation: A website based community approach
    Item type: Other Conference Item
    Franke, Felix; Meier, Philipp; Sobolev, Andrey; et al. (2012)
    Frontiers in Neuroinformatics
  • Advancing perfused BBB-on-chip technologies for throughput preclinical development
    Item type: Other Conference Item
    Wei, Wei; Gomes, Catarina; Traggiai, Elisabetta; et al. (2025)
    The 2nd Barcelona Blood-Brain-Barrier (B4) Conference. Book of Abstracts
  • Microtechnology and microelectronics to characterize neurons and networks at subcellular resolution
    Item type: Other Conference Item
    Hierlemann, Andreas (2021)
  • High-density microelectrode array recordings and real-time spike sorting for closed-loop experiments: an emerging technology to study neural plasticity
    Item type: Journal Article
    Franke, Felix; Jäckel, David; Dragas, Jelena; et al. (2012)
    Frontiers in Neural Circuits
    Understanding plasticity of neural networks is a key to comprehending their development and function. A powerful technique to study neural plasticity includes recording and control of pre- and post-synaptic neural activity, e.g., by using simultaneous intracellular recording and stimulation of several neurons. Intracellular recording is, however, a demanding technique and has its limitations in that only a small number of neurons can be stimulated and recorded from at the same time. Extracellular techniques offer the possibility to simultaneously record from larger numbers of neurons with relative ease, at the expenses of increased efforts to sort out single neuronal activities from the recorded mixture, which is a time consuming and error prone step, referred to as spike sorting. In this mini-review, we describe recent technological developments in two separate fields, namely CMOS-based high-density microelectrode arrays, which also allow for extracellular stimulation of neurons, and real-time spike sorting. We argue that these techniques, when combined, will provide a powerful tool to study plasticity in neural networks consisting of several thousand neurons in vitro.
Publications1 - 10 of 414