Wednesday, August 24, 2011

Lasers - Mending a Broken Heart

When most people think of lasers, many applications come to mind. Boring PowerPoint presentations aside, lasers are used for cutting, etching, and burning materials in industrial processes. With all the warning labels on most lasers about damaging your eyes, burning your skin, or otherwise injuring yourself, you might think that lasers are only dangerous instruments that cause harm when misused. For the most part, that is correct, but there are other uses with which you may not be familiar.

A different type of laser (non-cutting) is starting to show serious promise in several medical applications. Lasers are used in dentistry to both reduce the chance of an infection following oral surgery and even treat infections if they do arise. Low level laser therapy (LLLT), in many studies, significantly reduces pain and inflammation, heals wounds (surgical and accidental) faster and with less scarring, and can even promote healing in parts of the body well beyond the site of application. Laser light may even be effective in mending a broken heart...

Heart attacks occur when the heart is starved of oxygen rich blood. Usually one or more arteries that supply the heart become blocked leading to an area that dies in the heart wall. It is in this area that scarring occurs as the heart tries to repair itself. A promising new approach may lead to a remarkably effective treatment for those suffering heart attacks.

In a new study, laser “activated” stem cells found in bone marrow and injected into the blood stream can reduce the scarring and increase artery repair and regrowth following heart attack. The process used in this study involves exposing a type of stem cell found in bone marrow to low-level laser light. This exposure, in a manner that is not entirely understood, “energizes” the stem cells which allows them to better repair damage, in this case, in and around the heart.

In this animal test, using this approach, scarring was reduced by up to 80% and arteries supplying crucial oxygenated blood to the heart regrew up to 70%. While this is not a full recovery or regeneration to the exact state the heart was in before the heart attack, these results are better than traditional treatments or even stem cells alone. This new, non-invasive procedure holds great promise for effectively and safely treating people following heart attacks.

Stem Cells

Stem cells are cells that are capable of changing into many different types of cells. When we start our lives as a tiny single cell, that cell contains the DNA blueprint that makes up every cell of our adult bodies. One cell multiplies into two, two into four, and so on until a certain point where individual cells start to differentiate, or “branch” out. Bone, skin, muscle, neurons, stomach, hair, nails, and literally every part of you comes from that one cell. The enormous potential of this starter cell hints at the healing capability that stem cells possess.

There are many types of stem cells. Perhaps the most controversial type of stem cell is the embryonic stem cell. Embryonic stem cells, as the name suggests, are harvested from embryos, usually in the first stage of stem cell differentiation. While this type of stem cell is pluripotent (able to develop into almost all of the more than 220 cell types in the adult body) there are obviously serious ethical issues which arise with destroying embryos to obtain them.

A typical external low-level laser
therapy application.
In this case, the stem cells used are not embryonic stem cells but rather mesenchymal stem cells (MSCs). This type of stem cell exists in our bodies already, primarily in bone marrow and fat. They are particularly useful, as they can also grow and differentiate into many different types of cells used in the body, including bone, cartilage, fat, neurons, and vascular structures (veins and arteries). This ability to differentiate into so many types of cells allows them to be used in the body for diverse types of repairs. In this study, the MSCs developed into new arteries, replacing and repairing damaged ones, and repaired scar tissue in and around the hearts of the subjects (rats) who recently had heart attacks (myocardial infarctions). The roles MSCs play in repairing damaged tissues are only just beginning to come to light.

Laser Powered Cells

Several theories exist as to why laser light causes these effects to occur. Mitochondria, the parts of cells that produce (chemical) energy, are sensitive to red and near-infrared light, the most commonly used wavelengths in laser light therapy. This photo-sensitivity stimulates the mitochondria to increase production of adenosine triphosphate (ATP), which is the “molecular unit of currency” in our bodies. Along with an increase to ATP, the laser light creates small amounts of chemicals, called “reactive oxygen species”. These small amounts are relatively harmless, but they signal to the body to release, and accumulate, antioxidants in the affected area, further promoting healing and repair of damaged tissues.

Low level laser therapy (LLLT) is a new and rapidly developing branch of medicine. There are many variables to each treatment (wavelength, frequency, duration, intensity, pulsed/continuous, etc.) and no standardized method of communicating these, even within the community of researchers working in this field. With more research, hopefully these issues will be resolved and we can begin to understand the full capacity of healing which lasers and stem cells can allow.

Special thanks to:

Peter Jenkins of Spectra-Medics for providing the laser system pictured above.
Nelson Marquina, DC, PhD of USA Laser Biotech for bringing this new research to our attention.
Barry Kaye, DC for bringing this research to our attention

other resources:

Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

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