Laser Interactions and Stimulation Effects in Biological Material and the Limits of Stimulatory Effects of Low Power Density He-Ne Laser Radiation on Animal Fibroblasts Proliferation in Vitro

The effects of low power densities of some laser on stimulation of fibroblasts proliferation as well as some other bio-materials is studied where the mechanisms of laser treatments are not resolved. This is the continuation of previous investigation studied in the fibroblasts of different origins. The effects of low power density He-Ne laser irradiation on stimulation of fibroblasts proliferation in cell culture in vitro, found in some experiments, was probably the result photo-chemical effect. In our previous experiment this effect was shown in the range of energy density from 0.5 J/cm2 to 2.0J/cm2 without measurable increase of temperature. This effect is still not clear, because energy of He-Ne laser is not high. It could be that high energy density levels of radiation produce the effect contrary to stimulation. Our decision is to determine the lower threshold of He-Ne laser radiation (energy density below which the stimulation does not occur), as well as the upper limit of energy density which produce the same effect