Scientists trying gene therapy to create biological pacemaker

Scientists are in the process of creating a biological pacemaker by injecting a gene into the hearts of sick pigs that changed ordinary cardiac cells into a special kind that induced a steady heartbeat.

The study, published yesterday, comes as a step toward developing an alternative to electronic pacemakers implanted into 300,000 US citizens every year.

The Seattle Times, quoted Dr Eduardo Marban, director of the Cedars-Sinai Heart Institute in Los Angeles, who led the work as saying, there were people who desperately needed a pacemaker but could not get one safely.

He added the development heralded a new era of gene therapy that one day might offer them an option.

Human heartbeat depended on a natural pacemaker, a small cluster of cells, about the size of a peppercorn, according to Marban, that generated electrical activity.

Called the sinoatrial node, it acted like a metronome to keep the heart pulsing at 60 to 100 beats a minute or so, more when one was active, but if that node quit working correctly, hooking the heart to an electronic pacemaker worked well for most people.

However, around 2 per cent of recipients developed an infection that required the pacemaker to be removed for weeks until antibiotics wiped out the germs, according to Marban. Further some foetuses were at risk of stillbirth when their heartbeat faltered, a condition known as congenital heart block.

According to Marban, initially they thought that biological pacemaker cells could be a temporary bridge therapy for patients who had an infection in the implanted pacemaker area, the results however showed that with more research, they might be able to develop a long-lasting biological treatment for patients, ANI reported.

The laboratory findings could lead to clinical trials for humans with heart rhythm disorders but who suffered side effects, such as infection of the leads that connected the device to the heart, from implanted mechanical pacemakers.

According to Eugenio Cingolani, MD, the director of the Heart Institute's Cardiogenetics-Familial Arrhythmia Clinic in the future, pacemaker cells also could help infants born with congenital heart block.

According to Shlomo Melmed, dean of the Cedars-Sinai faculty, the work by Marban and his team heralded a new era of gene therapy, in which genes were used to not only correct a deficiency disorder, but to actually turn one kind of cell into another type.

The peer-reviewed journal Science Translational Medicine has published the study in its print edition.