Assessment of Human Lung Macrophages After Exposure to Multi-Walled Carbon Nanotubes. Part 2. DNA Damage.

摘要

Due to the widespread production and use of carbon nanotubes in almost every area of science (i.e., drug delivery, biosensors, fuel cells and thermal management systems), they are receiving considerable attention for their novel mechanical, electrical and chemical properties. At this time of high exposure potential, it is critical to ascertain the biological impact of these materials on likely target organs, tissues and cells, such as those of the lung. The aim of this study was to evaluate the degree of DNA damage to human lung macrophage (U937) cells after exposure to unpurified or acid- purified multi-walled carbon nanotubes. Cells were incubated with multi-walled carbon nanotubes and assessed for DNA damage response via fluorescent staining and a virtual gel electrophoresis technique. The results demonstrate that multi- walled carbon nanotubes may induce an early (2 4 h) stress response and contribute to DNA mismatch during cell replication. Similarly, after 24 h, the direct assessment of DNA damage revealed an overall reduction and degradation in total cellular DNA. Therefore, before nanomaterials are fully accepted and integrated into biological systems, they will continue to undergo further scrutiny at various stages of their processing (i.e., before and after purification) and with models ranging from simple to complex (i.e., cells vs. whole animals) to gain a better understanding between their physicochemical properties and bio-effects.