From University of Michigan:
Cardiac arrhythmia is caused by malfunctions in a certain type of heart muscle cells, which normally help regulate the heartbeat. Today, the disease is usually treated with drugs, which can have serious side effects. It can also be treated with a procedure called cardiac ablation that burns away the malfunctioning cells using a high-powered laser that’s threaded into the heart on a catheter. The laser also damages surrounding cells, which can cause artery damage and other serious problems.
The team, led by Jerome Kalifa, a cardiologist and U-M Medical School assistant professor of internal medicine and Raoul Kopelman, a chemist, materials scientist and the Richard Smalley Distinguished Professor of Chemistry, Physics and Applied Physics, set out to target and destroy the cells with a far more precise technique that uses low-level red light illumination instead of a high power laser. Widely used today to treat cancer, the technique requires doctors to mark unwanted cells with a chemical that makes them sensitive to low-level red light. The red light then destroys the marked cells while leaving surrounding tissue unharmed.
The team tested a treatment that delivers the photo sensitizing chemical (made from algae) to the targeted cells by injecting nanoparticles loaded with both the chemical and an amino acid-based peptide that causes the nanoparticles to be taken up only by the targeted cells. Red light is then delivered to the area using a procedure similar to today’s cardiac ablation. The low-level light destroys only the cells that have absorbed the nanoparticles, leaving the other heart cells unharmed.