title: EPR investigation of the gamma-ray irradiated natural and tanned collagen.
abstract: Free radicals produced in natural and tanned collagen by gamma-ray irradiation within 1-15 kGy absorbed dose ranges were investigated by EPR spectroscopy. Tanned collagen was prepared using formaldehyde as well as aluminum basic salts [Al(OH)SO4] tanning processes. Both natural and formaldehyde-tanned irradiated collagen show the same kind of EPR spectrum consisting of a single broad, slightly asymmetric line. Irradiated collagen tanned by aluminum basic salts process displayed a complex EPR spectrum consisting of a superposition of broad and narrow lines. A computer simulation of this spectrum allowed to evidence the presence of seven different kinds of paramagnetic centers, including those observed in the irradiated natural collagen. Corresponding Spin Hamiltonian parameters (g-factor, hyperfine splitting constant) as well as relative concentrations of these centers were calculated. Experimentally determined relative concentrations display a positive correlation with the absorbed dose described by a linear-type dependence. After three weeks of storage at room temperature, the concentration of some centers diminished by about 50%. The possible nature of these centers is discussed in connection with the local structure of the tanned collagen.
authors: Department of Atomic and Nuclear Physics, University of Bucharest, Romania. odlu@scut.fizica.unibuc.ro
authors: O G
authors: OG
authors: Duliu
authors: M
authors: M
authors: Epuras
authors: V
authors: V
authors: Trandafir
mesh_terms: D003094:Collagen / Q000737:chemistry* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004578:Electron Spin Resonance Spectroscopy; D005720:Gamma Rays; D013633:Tanning
chemical_list: D003094:Collagen