Scientists have developed a new method of treating arrhythmia by using nanoparticles to pinpoint heart cells targeted for laser therapy.
Arrhythmia is a life-threatening type of heart disease due to irregular heartbeat. Laser ablation is a method of treating arrhythmia, which uses light energy directed at the heart to destroy the cardiac muscle cells (myocytes) that are causing abnormal heart rhythm. However, complications may occur after treatment due to damage to surrounding healthy heart cells or tissues.
In a study published in Science Translational Medicine, researchers designed tiny synthetic materials or nanoparticles that are small enough to fit into the heart blood vessels and attach specifically to myocytes. These nanoparticles recognize a protein found only on myocytes and also contain a molecule, called a photosensitizer, that produces a type of oxygen that destroys target cells upon stimulation with laser.
In experiments in rats, nanoparticles were injected into the animals and after one hour, a laser beam was focused on the part of the heart containing myocytes for 10 to 15 minutes. The myocytes were effectively removed by laser therapy in nanoparticle-treated animals with no damage to surrounding tissues or blood vessels compared to untreated animals. All treated animals recovered and survived after the procedure. In another set of experiments, the combination of nanoparticles and laser therapy could restore arrhythmia to a normal heartbeat in treated animals.
According to the study, the new technique is a safe and noninvasive procedure that could be adapted and optimized for human use to treat arrhythmia patients.
Avula UMR, Yoon HK, Lee CH, Kaur K, Ramirez RJ, Takemoto Y, Ennis SR, Morady F, Herron T, Berenfeld O, Kopelman R, Kalifa J. Cell-selective arrhythmia ablation for photomodulation of heart rhythm. Sci Transl Med. Published online on 28 October 2015; 7(311): 311ra172. DOI: 10.1126/scitranslmed.aab3665
Written by Ana Victoria Pilar, PhD