Pulsed UV laser generated short-lived free radicals from biological samples

EPR characterization of the short-lived free radicals generated by pulsed UV laser ablation of biological samples has been investigated using a spin trap method. The obtained EPR spectra suggest that the trapped short-lived free radicals generated by excimer laser ablation of collagen and myocardium are identical. The obtained results are discussed in association with the production scheme of free radicals and an empirical mechanism of laser generated short-lived free radicals.

Direct observation of laser generated free radicals from a myocardium target site

The first direct observation of unstable free radicals generated by laser irradiation of myocardium samples has been performed by EPR at 100 K. Characteristic iron signals are measured for pulsed laser ablation of the sample. The EPR results are discussed in relation to the relative efficiency of the various types of lasers to produce free radicals. A comparison is made of the types of free radicals produced by the action of pulsed vs continuous wave (cw) laser energy.