Lasers stimulate stem cells for heart repair

Ashley N. Paddock, ashley.paddock@photonics.com

A noninvasive procedure uses laser-treated bone marrow stem cells to restore heart function and health after a stroke or heart attack.

After a heart attack or stroke, scarring can lead to paper-thin heart walls and a decreased ability to pump blood through the body. Although the heart contains some stem cells, which serve as the body’s repair system, they cannot completely repair the damage after an injury.

But a simple new process significantly reduces heart scarring after an ischemic event. Discovered by professor Uri Oron at Tel Aviv University, the method, called shining, consists of applying low-level laser energy to living bone marrow stem cells a few hours after a heart attack. This procedure reduces scarring by up to 80 percent.

“We were inspired by our previous work that demonstrated that treating stem cells with low-level laser energy prior to their implantation to the ischemic heart (cell therapy) resulted in beneficial effects to the heart as compared to non-laser-treated cells that were implanted to ischemic hearts,” Oron said.

A new technique applies low-power laser energy to stem cells to stimulate repair of cardiac cells after a heart attack or stroke. Here, representative cross sections of the heart demonstrate reduction of scarring in laser-treated rats. Courtesy of Uri Oron, Tel Aviv University.

Oron and his team performed this therapy on an animal model to determine its effectiveness, monitoring the flow of bone marrow stem cells with a fluorescent marker. They observed an increase in the stem cell population within the heart, specifically in the injured regions. The test group that received the shining treatment showed a higher concentration of cells in the injured organ compared with the group that had not been treated with lasers.

The technique is safer and simpler compared to other treatment options, such as harvesting stem cells from bone marrow and inserting them into the heart muscle. Oron said that, because it doesn’t require the removal of stem cells, the treatment could stimulate a variety of stem cells to help the body – inducing a “cocktail” that is more efficient than single-cell-type treatments.

The team conducted a series of safety studies to rule out the possibility that the laser stimulation of the stem cells could encourage abnormal tissue growth. Under the specific low doses of energy applied in this technique, no such danger was observed. The technique is now ready for clinical trial.

Next, Oron’s team plans to better define the photobiostimulated cells in the bone marrow and to follow their migration through the bloodstream to the heart. They will investigate the role of the laser-stimulated stem cells in attenuation of the processes post-myocardial infarction and will study the long-term safety of the method with regard to various organs.

The study was published in the July issue of Lasers in Surgery and Medicine (doi: 10.1002/lsm.21063).