Optimized Ratiometric Voltage-Sensitive Dyes for Cardiac Research, Safety Pharmacology

Project Summary/Abstract Potentiometric Probes
The overall goal of this Phase II SBIR project is to commercialize tools, invented by the
founders of Potentiometric Probe, LLC, for high-fidelity optical recording of electrical activity in
cardiac cells, tissues, and whole hearts. Potentiometric Probes develops organic
voltage-sensitive dyes (VSDs) that convert the changes in voltage across cell membranes to
visible changes in fluorescence. Instead of individual electrodes, this technology enables the
use of sensitive high-speed cameras, where each pixel can be considered an electrode, for
massively parallel high throughput screening, or for high-resolution spatiotemporal maps of
electrical signal propagation. Importantly, our VSDs are unique in enabling dual-wavelength
ratiometric recording of electrical activity; this is particularly important for cardiac studies
because it eliminates contraction-induced motion artifacts, permitting high-fidelity records of the
action potential waveform. Human stem cell-derived cardiomyocytes (hiPSC-CMs) and tissues
derived from them are increasingly being used for research and development purposes,
including screening new drugs for cardiotoxicity, and in the future may be used for “personalized
medicine” and the analysis of patient-derived cells. We believe high throughput recording of
accurate action potential waveforms from hiPSC-CMs and tissues will be a major market for the
proposed technology. Ultimately, the technology may also be applied clinically for
high-resolution imaging of action potential propagation in the heart. In this proposal,
Potentiometric Probes will synthesize a set of stable, non-toxic ratiometric VSDs with a broad
selection of spectral windows, allowing accurate recordings even from beating hearts. The
performance of these VSDs will also be fully characterized and validated for their compatibility
with sensitive cell lines for both long-term and high-throughput recordings.

Grant Number: 5R44GM152985-02
NIH Institute/Center: NIH
Principal Investigator: Corey Acker