Alpha keratin amino acids BEHVIOR under high FLUENCE laser interaction. Medical applications

摘要

A new method to produce keratin thin films using Pulsed Laser Deposition (PLD) is studied herein in order to obtain composite materials with application for medical purposes while being investigated alpha-keratin physicochemical behavior during compared procedures. The novelty of the method consists in using direct wool fibers and horn bulk as targets, irradiated with a 10 ns pulsed laser, 532 nm wavelengths, 25 J/cm(2) and 37 J/cm(2) fluence, for ablation followed by deposition on different substrates (glass and hemp fabric). This method has the advantage that eliminates preparatory steps, extracting the keratin directly from the raw material. It provides a "two faces" composite material with different sorption properties, enhanced for the face with keratin film.Thin films were analyzed compared to raw materials - wool and horn - as well as materials produced by two alkaline dissolution methods of the wool. Thus, the FTIR analysis revealed changes in the chemical structure of the films compared to that of the wool and horn used as targets due to the breakage of the disulfide bonds and the hydrogen bonding, as well as the breaking of the O = C-O bonds. This indicates a decrease in the length of the polypeptide chains from wool and from horn to pulsed laser deposited keratin. The most of the aforementioned bonds changes appear to occur during pulsed laser deposition from wool, while the chemical structures of the films produced by PLD are very close to that of keratin from the horn, as evidenced in the FTIR analysis.The main property of the keratin to absorb water proves to be preserved in the thin films too, and same the optical properties of transmittance and absorbance. The method is applicable for medicine purposes. Laser Induced Fluorescence of same high fluence as for PLD study of keratin from horn and PLD obtained films evidence chemical dissociation into radicals, and different other type of reactions such as those resulted from burning hydrocarbons.