An optogenetic pacemaker would march to a fiber-optic beat

A bioengineer is on her way to building a better pacemaker using light, rather than electricity, to get the heart ticking in rhythm. Technology Review tells us about work led by Emilia Entcheva, a bioengineer at SUNY Stony Brook, who presented her study in the journal Circulation: Arrhythmia & Electrophysiology. She employed optogenetics--use of genetic manipulation combined with pulses of light to stimulate heart tissue to beat.

The technique involves genetically programming cells with proteins that are sensitive to light, so they can be activated by pulses of low-energy blue light. The problem, though, is that the heart is a fairly large organ and it is not possible to introduce these light-sensitive genes into every single cell. The solution Entcheva came up with is to genetically alter a relative few number of cells to act as a kind of drum major--pulling the rest of the heart along to the rhythm. The research team tried it, and it worked. When stimulated by light, the cells all pulsed to the rhythm.

Entcheva envisions harvesting patients' own cells and injecting about a half-million of them (a couple of millimeters worth) into the heart. And, rather than electricity powering the whole thing, she envisions thin fiber-optic cables. This is a recipe, she says, for a new efficient kind of pacemaker. Until we get to that point, though, it can also be a decent research tool for those looking for possible cardiac side-effects to drugs being tested.

- read the article in Technology Review
- and the abstract in Circulation: Arrhythmia & Electrophysiology