A novel AFM-MEA Platform for Studying the Real Time Mechano-Electrical Behavior of Cardiac Myocytes
- PDF / 228,101 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 25 Downloads / 160 Views
1261-U04-09
A novel AFM-MEA Platform for Studying the Real Time Mechano-Electrical Behavior of Cardiac Myocytes Jose F. Saenz Cogollo1, Mariateresa Tedesco1, Sergio Martinoia1 and Roberto Raiteri1 1 Department of Biophysical and Electronic Engineering – DIBE, Università di Genova, Via Opera Pia 11a, 16145 GE, Italy. ABSTRACT We present a novel experimental platform based on a combined Atomic Force Microscopy (AFM) and Micro-Electrode Array (MEA) set-up. We have used it to measure minimal changes in the morphological/mechanical properties of electrically active cell cultures as well as to measure the changes in the extracellular electrical activity when a single cell is stimulated by means of the AFM tip. In particular, we studied the dynamical changes in cell elasticity of embryonic rat cardiac myocytes along the contraction-relaxation cycle. Applying high load indentations, we also recorded the effects of mechanical stimulations on the cell electrophysiology. The dynamic elastic modulus of the cell related to the contraction-relaxation cycle reveals a temporal behavior that closely follows the changes in cell height. Observed values of dynamic elastic modulus at a maximum indentation depth of 1500nm varied between 8.93 ± 0.78 kPa during systolic (contraction) phase and 4.26 ± 0.47 kPa during diastolic (relaxation) phase. Induced electrophysiological responses were observed when applying loads in the range 40-150 nN. The probability P of recording an induced electrical response (P = 0.16 for a maximum load of 100nN) increased with the maximum applied load. Pulling-like stimulations due to the tip-cell adhesion could also evocate electrical responses. INTRODUCTION Cardiac cells have been studied in great detail in the last decades, mainly by purely electrophysiological or purely mechanical methods. Although the electrophysiological processes of cardiac myocytes are widely understood, some dynamic mechanical properties of the myocardium remain undetermined at the single cell level [1], and important issues of the coupled mechano-electrical behavior of native and engineered cardiac tissue deserve more emphasis [2, 3]. The Atomic Force Microscope (AFM) and the Microelectrode Arrays (MEAs) allow high resolution and flexibility in morphological/mechanical and electrical domain respectively [4, 5], but until now they have never been used in conjunction for study the mechano-electrical behavior of actively beating cardiac myocytes. In the present work, we propose a new experimental platform based on the combination of the AFM and MEA techniques to perform precise-and-local mechanical characterization and stimulation on living cells while measuring in situ and in real time changes in their extracellular electrical activity. We applied this combined set-up to perform controlled indentations to single cardiac myocytes and study the local mechanical properties and the possible induced electrophysiological alterations. Such approach allows investigation, at the single cell level, of the cardiac electro-mechanics and the Mechano
Data Loading...
