Real-time visualization of cardiac cell beating behaviour on polymer diffraction gratings

Cardiotoxicity is one of the major adverse effects of pharmaceuticals and new methods are sought for measuring cell properties with high-throughput. Here we report a flexible diffraction grating device fabricated from polydimethylsiloxane coated with platinum to make optically responsive cell culturing substrates. Cardiomyocytes from neonatal Sprague-Dawley rats were isolated and seeded upon the surface of the PDMS diffraction grating using fibronectin as the binding protein. On this substrate the cells formed a confluent layer and continued beating synchronously. By measuring the optical change of the PDMS substrate, the beating of the confluent layer could be monitored. Epinephrine was introduced to the cell environment and the change in beating frequency was measured and visualized. This flexible diffraction grating substrate provides a new way for remotely measuring cell beating properties during high-throughput testing and within miniaturized or confined device architectures.