Carbon dots deposition in adult bones reveal areas of growth, injury and regeneration

ABSTRACTC-dots synthesized from carbon nanopowder (oxidation, hydrothermal) are particularly attractive theragnostic agents for bone-related injuries and disease due to their bright fluorescence and high binding affinity and specificity for bones, as demonstrated in a larval animal model. Larval bone development, however, is significantly different from the bone growth, repair and regeneration processes occurring in adults. Using adult zebrafish, we investigated C-dots’ interactions with adult skeletal structures. Upon injection, C-dots were observed at the surface of bones, at sites of appositional growth. In regenerating bones, C-dots were observed at the core and on the surface of the bones depending on the age of the tissue. C-dot’s deposition occurred within 30 min of delivery and it was highly selective. Importantly, their deposition did not interfere with bone regeneration or the animal’s health. Together, these properties establish C-dots as novel tools for the diagnostic and treatment of adult bone-related injuries and diseases.

The Energy Stored in the Aluminum Nanopowder Irradiated by Electron Beam

The influence of the electron beam irradiation on the parameters of aluminum nanopowder oxidation by heating in air was studied. It was found that the oxidation starts at the temperature in the range from 410° C to 460° C and independent on the radiation dose. The degree of oxidation varied from 44.4 % to 58.3 % and its dependence on the radiation dose was not established. The heat energy release occurred in two stages: at the first stage (up to ~ 660° C) in general the increase of the thermal effect was observed. At the second oxidation stage of irradiated aluminum nanopowder the growth of the thermal effect also observed. The peak of heat effect achieved by irradiation (45.0 kGy absorbed dose) was 2576 J/g higher than the thermal effect for non-irradiated aluminum nanopowder. The energy stored is an additional motivating factor in the synthesis of composite materials, intermetallic compounds, hydrogen producing reactions and synthesis of various kinds.