Experimental investigation of radioprotective properties of nanodiamonds
Objective: To assess experimentally radioprotective effect of ultradisperse nanodiamonds of detonation synthesis. Material and Methods: Radioprotective effect of oral administration of water suspension of nanodiamonds (ND) before x-ray exposure at a dose of 6.0 Gy was analyzed experimentally on white mongrel female rats weighing 180-210 g. The effects were traced on day 3, 7, 14, 30 using radiobiological, hematological, biochemical and pathoanatomical methods. Results: It was established that two oral administrations of ND suspension to the rats (0.5 mg/kg) 1 and 16 hours before x-ray exposure (LD <sub>70/30</sub>) relieved the course of radiation sickness, reduced manifestations of gastrointestinal syndrome and significantly decreased mortality (LD <sub>30-36,8/30</sub>). Hematological and biochemical investigations demonstrated less protective effect, which could be associated with the peculiarities of local contact mechanism of ND particles interaction with the cells of the gastrointestinal epithelium of the animals. Conclusion: Owing to radiation protection of the cells of the gastrointestinal tract, water suspension of ultradisperse diamonds of detonation synthesis possesses a marked radioprotective effect on the rats exposed to lethal dose. The state of other inner organs, hemopoietic system and the levels of a number of metabolism parameters in the exposed animals depend less on preliminary administration of ND.