Revealing the Healing Power of Light

Chukuka S. Enwemeka, dean of the College of Health Sciences and UWM Distinguished Professor of Kinesiology

Revealing the Healing Power of Light

Scientists have known for years that certain kinds of light in certain doses can heal wounds, but they don’t understand exactly how it works. UWM scientist Chukuka S. Enwemeka is on the forefront of revealing the cellular mechanisms of phototherapy.

A Brazilian woman had suffered for decades with a recalcitrant diabetic foot ulcer that wasn’t responding to any treatment. So her doctors, working with UWM’s Chukuka S. Enwemeka and his research team in Brazil, tried a new approach: They exposed the wound to specific doses of near-infrared light. Days later, she was pain-free, with full healing achieved within weeks.

Enwemeka, an internationally known researcher in phototherapy, who also is dean of UWM’s College of Health Sciences, is leading a research effort in Brazil and at UWM that he hopes will ultimately lead to the use of near-infrared and blue light to heal wounds and clear topical infections.

All types of light, including colors visible to the human eye, can be arrayed on a scale according to their wavelengths. Only a tiny portion of this scale, called the electromagnetic spectrum, is visible to us. Enwemeka and his team have shown that two kinds of light have certain beneficial properties – blue light in the visible range and invisible light in the range beyond red, called near-infrared (NIR). But Enwemeka and his colleagues have found each wavelength accomplishes the task in a very different manner.

NIR light can stimulate repair of damaged tissue. Enwemeka, UWM professors Janis Eells and Jeri Lyons, and UWM alumnus Harry Whelan, a professor at the Medical College of Wisconsin, have shown NIR light acts on the energy supply centers of cells, called mitochondria, and a particular enzyme called cytochrome c oxidase, to promote cell repair. Blue light, in contrast, heals infection by killing bacteria. Enwemeka’s studies with blue light suggest that it also acts on the same mitochondrial enzyme, but the effect is toxic to bacteria.

The theory is still unproven, but the therapy has gotten undeniable results in the lab with antibiotic-resistant “superbugs,” such as the deadly Staphylococcus aureus (MRSA). Enwemeka demonstrated that one dose of irradiation killed as much as 92 percent of two pervasive strains of the MRSA bacteria. Enwemeka hopes that getting the light to penetrate more layers of bacteria will eliminate the few bacterial colonies that survive irradiation. Working with UWM physics professor Valerica Raicu, he is developing technology that can bring the treatment into widespread clinical use.

The U.S. Food and Drug Administration is awaiting more evidence from a large-scale study before approving NIR treatment of chronic wounds and ulcers; something Enwemeka and Whelan are determined to accomplish. “To see people who have not had relief see their wounds heal and not return,” says Enwemeka, “is very touching.”