An EPR and optical spectroscopy study of the effect of laser radiation on biological tissues

The formation of radicals upon UV (248 nm) and IR (1.56 mum) laser irradiat ion of some biological tissues (cartilage, bone tissue, fish scale) and the ir components (chondroitin sulfate, collagen) was studied by the EPR techni que. The radical decay kinetics in bony tissue specimens after their irradi ation with UV light were described. By the spin trapping technique, it was shown that radicals were not produced during IR (1.56 mum) laser irradiatio n of cartilaginous tissue. A change in optical absorption spectra and the d ynamics of optical density of cartilaginous tissue, fish scale, and a colla gen film under exposure to laser radiation (248 nm) in an air, oxygen, and nitrogen atmosphere was studied.