Radiation Protection of Heparin in the Solid State

Radiation Protection of Hyaluronic Acid in the Solid State

“…There is a dramatic reduction in radical yield of the cetyl pyridinium complex, indicating that "electronic energy could be transferred" from the hyaluronate to the pyridinium group which is directly attached to the anionic group. From the pyridinium group the energy can be lost without C-H bond dissociation to form the H atoms, which are mainly responsible for the radical yield in cetyl pyridinium chloride (5).…”

“…In previous demonstrations of protection against radiation damage in glycosaminoglycans, criteria were utilized involving ESR spectral observations and chemical or physical changes during irradiation (5,17). Similar evidence for the protection of hyaluronic acid is sought in the present work using these methods.…”

“…In an attempt to develop methods which might be utilized to stabilize this glycosaminoglycan to radiation in the connective tissue matrix, we have examined the influence of ionizing radiations on hyaluronic acid alone and in association with the detergent cetyl pyridinium chloride. The latter was effectively used to protect heparin in the solid state (5), and the study revealed that solid glycosaminoglycans might in themselves allow "energy transfer." In the present study suitable radiation protection for hyaluronic acid was designed, and the ability of this polymer to sustain electronic energy transfer has been examined.…”

“…Absolute radical concentrations were determined at 2980K by comparison of the doubly integrated derivative ESR absorption spectra of the y-irradiated samples and glycine. The latter was used as a secondary standard for which G(radical) = 4.2 had been determined from dual cavity experiments using DPPH as a primary standard (5,11).1 Column chromatographic fractionation was conducted using a Dowex 1-C1 (200-400 mesh) column (1 X 50 cm). Elution was effected using a sodium chloride linear gradient at a flow rate of 6 ml/hr.…”

“…fitted with pyrex quartz seals and evacuated, were y-irradiated at 298 and 770K using a 10,000 Ci 60Co source at a dose rate of 3.5 X 10~7 eV g-1 min-'. The ESR spectrometer and accessories have been described previously (5,11).1 ESR spectra were recorded at a microwave power level not greater than 10-3-10-W (21-40 db) to minimize power saturation effects. Absolute radical concentrations were determined at 2980K by comparison of the doubly integrated derivative ESR absorption spectra of the y-irradiated samples and glycine.…”