Cells on a Chip - the Use of Electric Properties for Highly Sensitive Monitoring of Blood-Derived Factors Involved in Angiotensin II Type 1 Receptor Signalling

Abstract

Background: We developed a highly sensitive cardiomyocyte based screening system for the non-destructive electronic detection of chronotropic drugs and tissue-secreted factors involved in AT₁ receptor-mediated cardiovascular diseases. Methods: For this purpose we cultured spontaneously beating neonatal rat cardiomyocytes on microelectrode arrays (MEAs), and tested the optimised, stable culture parameters for a reproducible real-time recording of alterations in contraction frequency. After the evaluation of culture parameters, computer-based electronic measurement systems were used for counting of contractions by recording of the field potential of cardiomyocytes. Results: Using the biosensor, angiotensin II, the predominant ligand of the AT₁ receptor, was detected at very low concentrations of 10^-11 M via altered contractions of cardiomyocytes. Moreover, we demonstrated that cardiomyocyte coupled microarrays allow the detection of blood-derived low concentrated anti-AT₁ receptor autoimmune antibodies of pregnant women suffering from preeclampsia. Conclusion: This study demonstrates the first well-suited electrophysiological recording of cardiomyocytes on multielectrode arrays as a benefit for functional biomonitoring for the detection of AT₁ receptor/ligand interactions and other marker proteins in sera directed to cardiovascular diseases.

Electromagnetic exposure of scaffold-free three-dimensional cell culture systems

“…Temperature is a crucial parameter for electrically excitable cells. A previous study demonstrated a linear correlation between increasing temperature and contraction frequency of cardiac myocytes [Rothermel et al, 2005], which is in good agreement with our findings. To exclude thermal effects, all exposure experiments were performed using a temperature controller to maintain the temperature at 37 8C.…”

Real-Time Measurement of PMA-Induced Cellular Alterations by Microelectrode Array-Based Impedance Spectroscopy

“…For immunolabeling, MCF-7 cells were fixed with 4% formaldehyde for 30 min at room temperature. Immunofluorescence labeling was carried out as previously described (14). The rabbit polyclonal primary antibody anti-occludin (Santa Cruz Biotechnology, Santa Cruz, CA, USA) was used at a concentration of 1 g/mL.…”

Cytomics and nanobioengineering

“…Among others, the cardiomyocyte biosensor based micro-sensors were used for counting contractions by extracellular recording of field potential. Therefore, angiotensin II, the ligand of the AT1 receptor with a positive chronotropic activity, was detected at very low concentrations of 10 211 M. At the interface of micro-sensor system technology and cellular bioengineering, a multi-microelectrode array (MMEA) has been designed for the real time screening of cardiomyocyte ischemia in real time and online (31).…”

“…Thus, the presented technique can be of great benefit for the pharmaceutical industry, especially in respect of functional lead identification, the developing of individualized therapies and safe drug development processes. These assays in combination with the outstanding quality of materials constitute the basis for constant analysis of the cells in vitro and may as well support quality control of industrial bioprocesses, biotechnology,and pharmacy (31,36,37). Innovations like laser nanoelectricbeam surely can improve the precision of the measurements with focus on single cell analysis (37).…”