TY  - JOUR
A1  - Uysal, Karya
A1  - Firat, Ipek Serat
A1  - Creutz, Till
A1  - Aydin, Inci Cansu
A1  - Artmann, Gerhard
A1  - Teusch, Nicole
A1  - Temiz Artmann, Aysegül
T1  - A novel in vitro wound healing assay using free-standing, ultra-thin PDMS membranes
JF  - membranes
N2  - Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums. By using stainless steel balls, circular cell-free areas were created in the cell layer (wounding). Sinusoidal strain of 1 Hz, 5% strain, was applied to membranes for 30 min in 4 sessions. The gap circumference and closure rate of un-stretched samples (controls) and stretched samples were monitored over 4 days to investigate the effects of donor age and mechanical strain on wound closure. A significant decrease in gap circumference and an increase in gap closure rate were observed in trained samples from younger donors and control samples from older donors. In contrast, a significant decrease in gap closure rate and an increase in wound circumference were observed in the trained samples from older donors. Through these results, we propose the model of a cell monolayer on stretchable CellDrums as a practical tool for wound healing research. The combination of biomechanical cell loading in conjunction with analyses such as gene/protein expression seems promising beyond the scope published here.
Y1  - 2022
U6  - https://doi.org/10.3390/membranes13010022
N1  - This article belongs to the Special Issue "Latest Scientific Discoveries in Polymer Membranes"
VL  - 2023
IS  - 13(1)
PB  - MDPI
CY  - Basel
ER  - 
TY  - BOOK
A1  - Staat, Manfred
A1  - Heitzer, Michael
T1  - Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems.
Y1  - 2003
SN  - 3-00-010001-6
N1  - NIC Series Vol. 15 / Ed. by Staat, M; Heitzer, M.
PB  - John von Neumann Institute for Computing (NIC)
CY  - Jülich
ER  - 
TY  - JOUR
A1  - Bayer, Robin
A1  - Temiz Artmann, Aysegül
A1  - Digel, Ilya
A1  - Falkenstein, Julia
A1  - Artmann, Gerhard
A1  - Creutz, Till
A1  - Hescheler, Jürgen
T1  - Mechano-pharmacological testing of L-Type Ca²⁺ channel modulators via human vascular celldrum model
JF  - Cellular Physiology and Biochemistry
N2  - Background/Aims: This study aimed to establish a precise and well-defined working model, assessing pharmaceutical effects on vascular smooth muscle cell monolayer in-vitro. It describes various analysis techniques to determine the most suitable to measure the biomechanical impact of vasoactive agents by using CellDrum technology. Methods: The so-called CellDrum technology was applied to analyse the biomechanical properties of confluent human aorta muscle cells (haSMC) in monolayer. The cell generated tensions deviations in the range of a few N/m² are evaluated by the CellDrum technology. This study focuses on the dilative and contractive effects of L-type Ca²⁺ channel agonists and antagonists, respectively. We analyzed the effects of Bay K8644, nifedipine and verapamil. Three different measurement modes were developed and applied to determine the most appropriate analysis technique for the study purpose. These three operation modes are called, particular time mode" (PTM), "long term mode" (LTM) and "real-time mode" (RTM). Results: It was possible to quantify the biomechanical response of haSMCs to the addition of vasoactive agents using CellDrum technology. Due to the supplementation of 100nM Bay K8644, the tension increased approximately 10.6% from initial tension maximum, whereas, the treatment with nifedipine and verapamil caused a significant decrease in cellular tension: 10nM nifedipine decreased the biomechanical stress around 6,5% and 50nM verapamil by 2,8%, compared to the initial tension maximum. Additionally, all tested measurement modes provide similar results while focusing on different analysis parameters. Conclusion: The CellDrum technology allows highly sensitive biomechanical stress measurements of cultured haSMC monolayers. The mechanical stress responses evoked by the application of vasoactive calcium channel modulators were quantified functionally (N/m²). All tested operation modes resulted in equal findings, whereas each mode features operation-related data analysis.
Y1  - 2020
U6  - https://doi.org/10.33594/000000225
SN  - 1421-9778
VL  - 54
SP  - 371
EP  - 383
PB  - Cell Physiol Biochem Press
CY  - Düsseldorf
ER  - 
TY  - CHAP
A1  - Baader, Fabian
A1  - Reiswich, M.
A1  - Bartsch, M.
A1  - Keller, D.
A1  - Tiede, E.
A1  - Keck, G.
A1  - Demircian, A.
A1  - Friedrich, M.
A1  - Dachwald, Bernd
A1  - Schüller, K.
A1  - Lehmann, Raphael
A1  - Chojetzki, R.
A1  - Durand, C.
A1  - Rapp, L.
A1  - Kowalski, Julia
A1  - Förstner, R.
T1  - VIPER - Student research on extraterrestrical ice penetration technology
T2  - Proceedings of the 2nd Symposium on Space Educational Activities
N2  - Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process.
Y1  - 2018
SP  - 1
EP  - 6
ER  -