ao7b00339_si_001.pdf (1.79 MB)
Intracellular Trafficking of Fluorescent Nanodiamonds and Regulation of Their Cellular Toxicity
journal contribution
posted on 2017-06-16, 11:33 authored by Neeraj Prabhakar, Meraj H. Khan, Markus Peurla, Huan-Cheng Chang, Pekka E. Hänninen, Jessica M. RosenholmIn this paper, cellular management of fluorescent
nanodiamonds (FNDs) has been studied for better understanding in the
design for potential applications of FNDs in biomedicine. The FNDs
have shown to be photostable probes for bioimaging and thus are well-suited,
for example, long-term tracking purposes. The FNDs also exhibit good
biocompatibility and, in general, low toxicity for cell labeling.
To demonstrate the underlying mechanism of cells coping the low but
potentially toxic effects by nondegradable FNDs, we have studied their
temporal intracellular trafficking. The FNDs were observed to be localized
as distinct populations inside cells in early endosomes, lysosomes,
and in proximity to the plasma membrane. The localization of FNDs
in early endosomes suggests the internalization of FNDs, and lysosomal
localization, in turn, can be interpreted as a prestate for exocytosis
via lysosomal degradation pathway. The endocytosis and exocytosis
appear to be occurring simultaneously in our observations. The mechanism
of continuous endocytosis and exocytosis of FNDs could be necessary
for cells to maintain normal proliferation. Furthermore, 120 h cell
growth assay was performed to verify the long-term biocompatibility
of FNDs for cellular studies.