Almost every day, there are new and exciting announcements on ways that low level laser therapy can help keep us and our animals healthy. The following is from Valerie C. Coffey, Science Writer:
It started with mouse hairs. In 1967, Dr. Endre Mester of Semmelweis Medical University in Budapest, Hungary, recognized that a low-power ruby laser could stimulate faster hair regrowth in mice. Since then, lasers have increasingly become an important instrument in the physician’s toolbox.
Today, research is advancing toward the use of lasers to diagnose and treat a plethora of conditions. Recent rapid technological developments in lasers have contributed to their safe and effective use in surgical settings, aesthetic treatments, ophthalmology, oncology, cardiology and many other biomedical applications, including veterinary settings.
Lasers’ efficiency, safety and precision are the drivers behind this growth. In surgical applications, medical lasers are more precise than conventional surgical scalpels, and therefore cause less damage to surrounding tissue. Although systems are expensive and operators of medical lasers require special training, the advantages of reduced pain, bleeding, swelling and scarring are compelling enough to justify their widespread adoption.
Much current cutting-edge research is focused on biophysical and physiological studies at the molecular and cellular level, and on lasers’ effects on whole organisms. A group at the University of Texas at Arlington, led by assistant professor of physics Dr. Samarendra Mohanty, has used low-power near-IR lasers and crystalline magnetic carbon nanoparticles (CNPs) to perform photothermal delivery of impermeable dyes and plasmids (self-replicating DNA molecules) into live human prostate cancer (PC3) cells (Scientific Reports, doi: 10.1038/srep05106). The noninvasive technique involves directing a CW Ti:sapphire laser at 800 nm toward the cancer cells in the presence of plasmids and CNPs measuring 5-10 nm. The heat causes the CNPs to stretch the cell membranes and increase fluid flow to allow exogenous substances (plasmids, for example, or an agent that kills the cancer) to be delivered.
Laser therapy is one of several emerging medical and veterinary techniques using high-intensity light to stimulate cellular function in tissue, or to shrink and destroy tumors and precancerous growths. Doctors can direct laser therapy on the surface of a body, or use it to reach where conventional surgical techniques can’t, via a flexible fiber optic endoscope inserted through the mouth, nose, colon or vagina.
Photodynamic therapy is another laser therapy approach that activates an applied photosensitive agent that kills only the cancer cells.
Recent medical research theorizes that the mechanism of low-level laser therapy is primarily via the absorption of light within mitochondria, the numerous “power plants” within cells that convert the oxygen and pyruvate from food into cellular energy via adenosine triphosphate (ATP). As it happens, cytochrome C oxidase, a critical protein involved in the regulation of mitochondrial activity, is a photoacceptor of light in the near- to far-IR. At the cellular level, LLLT displaces nitric oxide from the respiratory chain to increase levels of ATP and reactive oxygen species. The deep-tissue application of laser or LED devices in LLLT techniques may work via this mitochondrial mechanism to promote tissue repair, reduce inflammation and induce analgesia, according to James Carroll, medical researcher, and founder and CEO of Thor Photomedicine in Chesham, England
In 2012, researchers at the Institute of Ophthalmology at University College London applied LLLT to eye disease. Researcher Dr. Rana Begum and colleagues found that when the retinas of aged mice were exposed to five 90-s exposures of 670-nm light over 35 hours, key inflammatory markers in the mitochondrial membrane were significantly reduced (Neurobiology of Aging). The hope is that, someday, the noninvasive approach may help to slow the progression of dry age-related macular degeneration, according to founder and CEO Clark Tedford.