1. NASA Light Emitting Diode Medical Applications From Deep Space to Deep Sea
   This work is supported and managed through the NASA Marshall Space Flight Center – SBIR Program. LED-technology developed for NASA plant growth experiments in space shows promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. We present the results of LED-treatment of cells grown in culture and the effects of LEDs on patients’ chronic and acute wounds. LED-technology is also biologically optimal for photodynamic therapy of cancer and we discuss our successes using LEDs in conjunction with light-activated chemotherapeutic drugs.

   Studies on cells exposed to microgravity and hypergravity indicate that human cells need gravity to stimulate growth. As the gravitational force increases or decreases, the cell function responds in a linear fashion. This poses significant health risks for astronauts in long-term space flight. The application of light therapy with the use of NASA LEDs will significantly improve the medical care that is available to astronauts on long-term space missions. NASA LEDs stimulate the basic energy processes in the mitochondria (energy compartments) of each cell, particularly when near-infrared light is used to activate the color sensitive chemicals (chromophores, cytochrome systems) inside. Optimal LED wavelengths include 680, 730 and 880 nm and our laboratory has improved the healing of wounds in laboratory animals by using both NASA LED light and hyperbaric oxygen. Furthermore, DNA synthesis in fibroblasts and muscle cells has been quintupled using NASA LED light alone, in a single application combining 680, 730 and 880 nm each at 4 Joules per centimeter squared.

   Muscle and bone atrophy are well documented in astronauts, and various minor injuries occurring in space have been reported not to heal until landing on Earth. An LED blanket device may be used for the prevention of bone and muscle atrophy in astronauts. The depth of near-infrared light penetration into human tissue has been measured spectroscopically (Chance, et al., 1988). Spectra taken from the wrist flexor muscles in the forearm and muscles in the calf of the leg demonstrate that most of the light photons at wavelengths between 630-800 nm travel 23 cm through the surface tissue and muscle between input and exit at the photon detector. The light is absorbed by mitochondria where it stimulates energy metabolism in muscle and bone, as well as skin and subcutaneous tissue. Read More >>

2. Medical Applications of Space Light-Emitting Diodes Technology—Space and Beyond
   Space light-emitting diode (LED) technology has provided medicine with a new tool capable of delivering light deep into tissues of the body, at wavelengths which are biologically optimal for cancer treatment and wound healing. This LED technology has already flown on space shuttle missions, and shows promise for wound healing applications of benefit to Space Station astronauts and in special operations.

Wound Healing
Wounds heal less effectively in space than here on Earth. Improved wound healing may have multiple applications which benefit civilian medical care, military situations and long-term space flight. Laser light and hyperbaric oxygen have been widely acclaimed to speed wound healing in ischemic, hypoxic wounds. Lasers provide low energy stimulation of tissues which results in increased cellular activity during wound healing. Some of these activities include increased fibroblast proliferation, growth factor synthesis, collagen production and angiogenesis. Hyperbaric oxygen therapy has also been shown to affect these processes.

Lasers, however, have some inherent characteristics which make their use in a clinical setting problematic, including limitations in wavelength capabilities and beam width. The combined wavelengths of light optimal for wound healing cannot be efficiently produced, and the size of wounds which may be treated by lasers is limited. Light-emitting diodes (LED’s) offer an effective alternative to lasers. These diodes can be made to produce multiple wavelengths, and can be arranged in large, flat arrays allowing treatment of large wounds. Our experiments suggest potential for using LED light therapy at 680, 730 and 880 nm simultaneously, plus hyperbaric oxygen therapy, both alone and in combination, to accelerate the healing process in Space Station missions, where prolonged exposure to microgravity may otherwise retard healing.

Studies on cells exposed to microgravity and hypergravity indicate that human cells need gravity to stimulate cell growth. As the gravitational force increases or decreases, the cell function responds in a linear fashion. This poses significant health risks for astronauts in long term space flight.

The application of light therapy with the use of NASA LED’s will significantly improve the medical care that is available to astronauts on long term space missions. NASA LED’s stimulate the basic energy processes in the mitochondria (energy compartments) of each cell, particularly when near-infrared light is used to activate the color sensitive chemicals (chromophores, cytochrome systems) inside. Optimal LED wavelengths include 680, 730 and 880 nm. Our laboratory has improved the healing of wounds in laboratory animals by using NASA LED light and hyperbaric oxygen. Furthermore, DNA synthesis in fibroblasts and muscle cells has been quintupled using NASA LED light alone, combining 680, 730 and 880 nm each at 4 Joules per centimeter squared. Read More >>

The full-length article is available in Space Tech. & App. Int’l. Forum -1999, vol 458:3-15. 1999-00, Medical College Of Wisconsin