This optical stimulation platform doesn’t miss a beat

Considering cardiovascular disease is the leading cause of death worldwide, it’s no wonder there’s so much research on cardiac cells. But studying these cells in isolation isn’t sufficient, because the cardiovascular system is controlled by electrochemical signals between cells.

Since stimulating the cells with external voltage pulses can be disruptive to cell cultures, Florindi et al. used optical pacing to achieve contactless stimulation using a molecule called Ziapin2.

“Our interest is in developing non-genetic strategies to modulate cellular electrical activity using light,” said author Chiara Florindi. “We chose Ziapin2 because it is a small organic photoswitchable molecule that can spontaneously insert into the cellular membrane after a short incubation, without the need for genetic modification or invasive delivery methods.”

Ziapin2 responds to light and can change the electrical potential of the cell membrane accordingly. This allowed the researchers to control cardiomyocyte activity with optical pulses and then measure the resulting signals with electrodes.

They combined this approach with a laser-based optoporation system, which uses highly localized pulses to temporarily and safely increase membrane permeability. This enabled the recording system to capture intracellular-like electrical signals with much higher detail than conventional extracellular recordings.

“Importantly, Ziapin2 is biocompatible and remains associated with the membrane for several days after a single incubation, providing stable and sustained functionality,” Florindi said. “These features make it particularly well-suited for repeated measurements, longitudinal studies, and high-throughput applications.”

The researchers then developed a software for automated analysis of electrophysiological signals in collaboration with FORSEE Biosystems. Future work will focus on further refining both the optical pacing platform and the software.

“On the stimulation side, we plan to implement the use of multiple wavelengths to adapt the system to different photostimulation strategies and photoactuators,” Florindi said.

Source: “A novel optoelectronic platform combining LED-driven pacing and laser optoporation for high-throughput cardiac electrophysiology,” by Chiara Florindi, Carolina Scandellari, Claudia Maniezzi, Giulia Bruno, Luca Sala, Annarita Di Mise, Guglielmo Lanzani, Chiara Bertarelli, Marcella Rocchetti, Antonio Zaza, Michele Dipalo, and Francesco Lodola, Biophysics Reviews (2026). The article can be accessed at https://doi.org/10.1063/5.0311976 .