RADIOLYSIS, PHOTOLYSIS AND SONOLYSIS OF CELLS AND THEIR CONSTITUENTS

细胞及其成分的放射分解、光分解和声分解

• 批准号: 3838056
• 负责人: P RIESZ
• 金额: --
• 依托单位: DIVISION OF CANCER TREATMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3838056
• 关键词: antineoplastics; ascorbate; combination cancer therapy; cytolysis; dimethylsulfoxide; doxorubicin; electron spin resonance spectroscopy; free radical oxygen; neoplasm /cancer photoradiation therapy; neoplasm /cancer radiation therapy; neoplasm /cancer therapy; photochemistry; photolysis; photosensitizing agents; phthalocyanin; radiosensitizer; riboflavin; singlet oxygen; solvents; ultrasound biological effect; ultrasound therapy

Phthalocyanines and their sulfonated derivatives show considerable promise to replace hematoporphyrin derivatives for photodynamic therapy (PDT) of human tumors. The ability of tissue-omnipresent ascorbic acid (Vitamin C) to deactivate photoexcited phthalocyanine with consequent formation of the electron spin resonance detectable ascorbate radical, brings new perspective to the understanding of the chemical mechanisms of photodynamic reactions. Our studies with chloraluminum phthalocyanine tetrasulfonate and riboflavin (Vitamin B2) as photosensitizers demonstrate free radical formation by direct reaction between ascorbate ion and the excited triplet state of the photosensitizer. This process is in competition with the reaction of ascorbate ion with singlet oxygen, a reaction which does not lead to the formation of ascorbate radicals. The chemical effects of ultrasound were investigated in relation to sonodynamic cancer therapy, a new approach in which the synergistic effects of combined ultrasound and anticancer drugs (e.g. Adriamycin) have been observed. The 50 kHz sonolysis of argon-saturated dimethyl sulfoxide-water mixtures was studied by electron spin resonance and spin trapping with 3,5-dibromo-4-nitrosobenzenesulfonate. While for previous sonolysis studies of aqueous mixtures of solvents more volatile than water, spin-adducts yields decrease at high mole fractions of the organic solvent because of the decreasing effective ratio of the specific heat at constant pressure to the specific heat at constant volume in the imploding argon cavitation bubbles, the pyrolysis product of dimethylsulfoxide increases with increasing dimethylsulfoxide concentrations.

酞菁及其磺化衍生物表现出相当大的毒性