Luminescence switchable carbon nanodots follow intracellular trafficking and drug delivery
Dipanjan Pan, an assistant professor of bioengineering and the leader of the study. “Using some elegant nanoscale surface chemistry, we created a molecular ‘masking’ pathway to turn off the fluorescence and then selectively remove the mask leading to regaining the brightness.
Tiny carbon dots have, for the first time, been applied to intracellular imaging and tracking of drug delivery involving various optical and vibrational spectroscopic-based techniques such as fluorescence, Raman, and hyperspectral imaging. Researchers from the University of Illinois at Urbana-Champaign have demonstrated, for the first time, that photo luminescent carbon nanoparticles can exhibit reversible switching of their optical properties in cancer cells.
“Using carbon dots for illuminating human cells is not new. In fact, my laboratories, and several other groups around world, have shown that these tiny dots represent a unique class of luminescent materials with excellent biocompatibility, degradability, and relatively facile access to large-scale synthesis in comparison to other popular luminescent materials such as quantum dots,” added Pan, who also directs the Professional Masters in Engineering Program in Bioengineering at Illinois.
And, the entire process of is highly controlled and can be observed in living cells as they reported in the group’s study, “Macromolecularly ‘Caged’ Carbon Nanoparticles for Intracellular Trafficking via Switchable Photoluminescence,” appearing in the Journal of the American Chemical Society.
“This can be reversibly turned on and off by a simple counter-ionic nanoscale chemistry,” Pan said. “These results can become the basis for new and interesting designs for carbon-based materials for intracellular imaging probing cellular function and to study other biological processes.”
While the origin of luminescence in carbon dots is still quite a mystery, Pan and his collaborators have previously demonstrated that these particles can be used to simultaneously track carrier and quantitative release of cargo using hyperspectral imaging (Advanced Functional Materials 26, 2016, 8031-8041) or vibrational spectroscopy based techniques (Sci Rep. 2016 Jul 11;6:29299.; Small. 2016 12 (42), 5845-861.; Small. 2015 Sep;11(36):4691-703).
Santosh Misra, a postdoctoral researcher, and Indrajit Srivastava, a graduate student in Pan’s lab co-contributed as study first authors. Co-authors included several members of the research group—Dr. Indu Tripthi, Enrique Daza, and Fatemeh Ostadhossein—who contributed to this work.