Using Lasers to Spur Stem Cells Into Action
A novel way to manipulate stem cells: "Though the heart is known to contain some stem cells, they have a very limited ability to repair damage caused by a heart attack [and] researchers have had to look elsewhere. One of the first efforts to use stem cells to reduce heart scarring involved harvesting them from the bone marrow and inserting them back into the heart muscle, close to the heart's blood supply, but this had limited success. Prof. Oron, who has long used low level lasers to stimulate stem cells to encourage cell survival and the formation of blood vessels after a heart attack, was inspired to test how laser treatments could also work to heal the heart. He and his fellow researchers tried different methods, including treating the heart directly with low level lasers during surgery, and 'shining' harvested stem cells before injecting them back into the body. But he was determined to find a simpler method. After a low-level laser was 'shined' into a person's bone marrow - an area rich in stem cells - the stem cells took to the blood stream, moving through the body and responding to the heart's signals of distress and harm ... Once in the heart, the stem cells used their healing qualities to reduce scarring and stimulate the growth of new arteries, leading to a healthier blood flow. To determine the success of this method, Prof. Oron performed the therapy on an animal model. Following the flow of bone marrow stem cells through the use of a fluorescent marker, the researchers saw an increase in stem cell population within the heart, specifically in the injured regions of the heart. The test group that received the shining treatment showed a vastly higher concentration of cells in the injured organ than those who had not been treated with the lasers."
Link: http://www.eurekalert.org/pub_releases/2011-08/afot-ta081011.php
Chemical effects of electromagnetic radiation are (I assume) due to effects on molecular bonds which may be enhanced by a nonstationary pulse train - possibly exceeding the effect of stationary monochromatic laser light. For example, see -
"Euclidean Resonance: Application to Physical and Chemical Experiments"
http://arxiv.org/PS_cache/quant-ph/pdf/0404/0404023v1.pdf
It would be interesting to know if the beneficial biological effects could be increased by irradiating the tissue with laser light sources of multiple frequencies (if possible phase-locked) or by some more complex shaped electromagnetic pulse trains. I am unaware of any experiments which used anything except spectrally pure laser light or narrow band incoherent light sources.