The Safety Applied Study Of Carbon Dots In The Biological And Medical Field

With the development of nano science and technology, a large number of nano-materials have used in bio-medicine, food science, industrial production, whether it is safe to humans and the environment in the application had attracted the attention of people. The new carbon quantum dots (Carbon dots, CDs) which can emiss stability fluorescence signal, regulate the wavelength and good biocompatibility and low toxic which was considered that CDs would widely applicated in the biological and medical field, and gradually became the focus of the carbon nanomaterials research.This article would be study the biological effects and possible mechanisms of carbon dots from the protein molecules, bacteria and cellular level by bovine serum albumin (BSA), Escherichia coli (E. coli) and human bronchial epithelial cells (16HBE cells).(1) BSA was used as a protein macromolecules model to study the interaction between CDs and protein using fluorescence spectroscopy (FL) and synchrotron radiation circular dichroism (SRCD). It was found that CDs could cause static quenching of fluorescence and the SRCD spectra change. And the CDs could form with BSA to a composite through a non-specific adsorption and cause the secondary and tertiary structure of BSA changed by further calculation. The results of this study could provide new inspiration in the field of biological effects, toxicological effects and their potential applications of CDs.(2) E. coli was used as a microorganism model to study the effect of the survival, intracellular reactive oxygen species (ROS) and membrane stability after exposure to CDs. The results showed that the CDs exposured have no significant effect on the growth, the intracellular reactive oxygen species and cell membrane of E. coli which suggested that CDs does not have significant toxic effects. And we discussed the mechanism and possible application of CDs in E. coli.(3) Human bronchial epithelial cells (16HBE Cell) cell was used to study the effect of CDs at the cellular level after exposure to CDs for24h. Some important biomarkers towards the human bronchial epithelial cell lines (16HBE cells) were measured, such as cell viability, lactate dehydrogenase (LDH), reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH), etc. We expect that these results will provide some useful information for better understanding the cytotoxicity of CDs and the underlying mechanisms.