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Eisenloffel C.,University of Rostock | Schmole A.-C.,University of Rostock | Pews-Davtyan A.,Leibniz Institute for Catalysis at the University of Rostock | Brennfuhrer A.,Leibniz Institute for Catalysis at the University of Rostock | And 9 more authors.
Biochemical Pharmacology | Year: 2013

Indolylmaleimides display a broad spectrum of biological activity and offer great opportunity to influence several aspects of cell fate, as proliferation and differentiation. In this study we describe the effect of PDA-66, a newly synthesised indolylmaleimide, showing a strong dose dependent anti-proliferative effect on immortalised human progenitor and cancer cells. We demonstrated a highly depolymerizing effect on in vitro tubulin assembly and conclude that PDA-66 acts as microtubule destabilising agent. In addition we found that PDA-66 induces mitotic arrest of cells in the G2/M phase of the cell cycle. Subsequently cells undergo apoptosis, indicating the major mechanism of the anti-proliferative effect. To prove a potential anti-cancer activity of PDA-66 we examined the effect of PDA-66 on human SH-SY5Y neuroblastoma and A-459 lung cancer cells, showing a significant reduction in cancer cell proliferation in a dose dependent manner. Thus PDA-66 is a new anti-mitotic compound with an indole-core with the potential to be used for cancer therapy. © 2012 Elsevier Inc.


Weltin A.,Albert Ludwigs University of Freiburg | Weltin A.,Jobst Technologies GmbH | Slotwinski K.,Albert Ludwigs University of Freiburg | Kieninger J.,Albert Ludwigs University of Freiburg | And 5 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2014

We present a novel, multiparametric microphysiometry system for the dynamic online monitoring of human cancer cell metabolism. The optically transparent, modular, hybrid microsystem is based on a glass chip and combines a cell cultivation chamber, microfluidics and metabolic monitoring with fully integrated chemo- and biosensors. pH and oxygen are measured in the cell culture area, and biosensors for lactate and glucose are connected downstream by microfluidics. The wafer-level fabrication features thin-film platinum and iridium oxide microelectrodes on a glass chip, microfluidics in an epoxy resist, a hybrid assembly and an on-chip reference electrode. The reliable analytical performance of the sensors in cell culture medium was demonstrated. The pH sensors exhibit a long-term stable, linear response. The oxygen sensors show a linear behaviour, which is also observed for low oxygen concentrations. Glucose and lactate measurements show a linear, long-term stable, selective and reversible behaviour in the desired range. T98G human brain cancer cells were cultivated and cell culture metabolism was measured on-chip. Stop/flow cycles were applied and extracellular acidification, respiration, glucose consumption and lactate production were quantified. Long-term metabolic rates were determined and all parameters could be measured in the outlet channel. A placement downstream of the cell cultivation area for biosensors was realised. A highly effective medium exchange and undiluted sampling from the cell culture chamber with low flow rates (2 μl min-1) and low volumes (15 μl per cycle) were achieved. The drug screening application was demonstrated by detecting alteration and recovery effects of cellular metabolism induced by the addition of substances to the medium. This journal is © 2014 The Royal Society of Chemistry.


Weltin A.,Albert Ludwigs University of Freiburg | Weltin A.,Laboratory for Sensors | Slotwinksi K.,Albert Ludwigs University of Freiburg | Kieninger J.,Albert Ludwigs University of Freiburg | And 4 more authors.
17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013 | Year: 2013

A novel multiparametric microsensor system for online cell culture monitoring with human tumor cells is introduced. The system combines cell culture, microiluidics and biosensors on a single chip. It features pH, oxygen, glucose and lactate sensors on a transparent chip. The sensor performance was proven in cell culture environment. Cellular metabolism of T98G brain tumor cells was measured. Extracellular acidification and respiration can be quantified. Medium was efficiently transported to the biosensors by microiluidics. Glucose consumption and lactate production was measured in cycles with low analyte volumes (< 15 μl). Alteration of cellular metabolism by compounds could be monitored successfully.


Weltin A.,Albert Ludwigs University of Freiburg | Kieninger J.,Albert Ludwigs University of Freiburg | Urban G.,Albert Ludwigs University of Freiburg | Moser I.,Jobst Technologies GmbH | And 3 more authors.
Proceedings of IEEE Sensors | Year: 2010

A novel microphysiometry platform for dynamic cell culture monitoring in drug screening and cancer cell research is presented. The transparent system features an integrated cell cultivation area, microfluidics and (bio-)sensors for multiparametric metabolic monitoring, combined on a single glass chip. The parameters include glucose and lactate (amperometric biosensors), oxygen (amperometric), pH (potentiometric) and cellular adhesion (interdigital electrode). In contrast to traditional silicon chip based systems, the choice of transparent materials allows microscopy at all times of cell cultivation and measurement. The introduction of biosensors allows the monitoring of additional key metabolic parameters with a detection limit for lactate as low as 2 μM. Integrated multi layer microfluidics enable dynamic measurements, further improving the analytical performance. The modular system is microfabricated in a cost-effective hybrid integration of thin film and laminate technology. ©2010 IEEE.


Thakur M.,Charité - Medical University of Berlin | Mergel K.,Charité - Medical University of Berlin | Weng A.,Charité - Medical University of Berlin | Frech S.,Bionas GmbH | And 4 more authors.
Biosensors and Bioelectronics | Year: 2012

This work describes the application of an impedance-based measurement for the real time evaluation of targeted tumor therapies in cell culture (HeLa cells). We used a treatment procedure that is well established in cells and mice. Therein, tumor cells are treated with a combination of an epidermal growth factor-based targeted toxin named SE and particular plant glycosides called saponins. In the present study HeLa cells were seeded in different numbers onto interdigitated electrode structures integrated into the bottom of a 96 well plate. The cells were treated with SE in the presence and absence of the saponin SpnS-1 (isolated from Saponaria officinalis roots). The impedance was directly correlated with the viability of the cells. As expected from known end point measurements, a concentration dependent enhancement of toxicity was observed; however, with the impedance measurement we were for the first time able to trace the temporal changes of cell death during the combination treatment. This substantially added to the understanding of initial cellular mechanisms in the augmentation of the toxicity of targeted toxins by saponins and indicated the superiority of real time monitoring over end point assays. The method is less labor intensive and label-free with ease of monitoring the effects at each time point. © 2012 Elsevier B.V.


Drechsler S.,Bionas GmbH | Andra J.,Research Center Borstel
Journal of Bioenergetics and Biomembranes | Year: 2011

Antimicrobial peptides are promising anti-cancer agents with a unique mode of action. We established the usage of a chip-based sensor to monitor the dynamic interplay between cells on the chip and peptides and compared it with endpoint tests. Human neuroblastoma cancer cells and spontaneously immortalized non-cancer keratinocytes were perfused with representative peptides (NK-2, NK11, and melittin). The sensor system enabled continuous recording of cell layer impedance (adhesion/confluence), oxygen consumption (respiration) and extracellular acidification (glycolysis) and provided insights in cell damage, stress response and recovery. Cells responded differentially to peptide treatment. During perfusion, peptides accumulated on the cell surface until they reached a critical concentration. Preceding to cell death, melittin triggered glycolysis, suggesting stress response. NK-2 induced no change in energy metabolism, but led to an increase in impedance, i.e. a temporarily altered morphology, which appeared to be an excellent parameter to detect subtle structural changes of cell layers. © 2011 The Author(s).


Abarzua S.,University of Rostock | Drechsler S.,Bionas GmbH | Fischer K.,University of Rostock | Pietschmann N.,University of Rostock | And 6 more authors.
Anticancer Research | Year: 2010

Background: Phytoestrogens are naturally occurring, plant-derived, nonsteroidal phytochemicals with anticarcinogenic potential. The aim of this study was to isolate phytoestrogens from the flax root of Linum usitatissimum and to test their effect on cellular metabolism in the human mammalian carcinoma cell line MCF-7 using the Bionas® 2500 analysis system. Materials and Methods: Metabolically relevant parameters such as acidification, oxygen consumption and cell adhesion were registered continuously over 8 and 24 hours on six sensor chips in parallel at different concentrations of flax root extracts. Results: The extracts from flax roots of L. usitatissimum reduced extracellular acidification, respiration and adhesion in a concentration- dependent manner. Conclusion: The Bionas® 2500 analysis system allows multiparametric online monitoring of cellular processes and can be used to detect the mode of action of anticarcinogenic compounds in cellular metabolism.

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