The Fate of Lipid-Coated and Uncoated Fluorescent Nanodiamonds during Cell Division in Yeast

Abstract

Fluorescent nanodiamonds are frequently used as biolabels. They have also recently been established for magnetic resonance and temperature sensing at the nanoscale level. To properly use them in cell biology, we first have to understand their intracellular fate. Here, we investigated, for the first time, what happens to diamond particles during and after cell division in yeast (Saccharomyces cerevisiae) cells. More concretely, our goal was to answer the question of whether nanodiamonds remain in the mother cells or end up in the daughter cells. Yeast cells are widely used as a model organism in aging and biotechnology research, and they are particularly interesting because their asymmetric cell division leads to morphologically different mother and daughter cells. Although yeast cells have a mechanism to prevent potentially harmful substances from entering the daughter cells, we found an increased number of diamond particles in daughter cells. Additionally, we found substantial excretion of particles, which has not been reported for mammalian cells. We also investigated what types of movement diamond particles undergo in the cells. Finally, we also compared bare nanodiamonds with lipid-coated diamonds, and there were no significant differences in respect to either movement or intracellular fate.

Single‐Particle Tracking and Trajectory Analysis of Fluorescent Nanodiamonds in Cell‐Free Environment and Live Cells

“…The nanodiamond trajectories were recorded using a home‐made confocal microscope, as described previously. [ 46 ] First, an individual FND would be selected from the single‐plane image of the sample, based on stable, non‐bleaching fluorescence, with at least 1 000 000 photon counts per second. The coordinates of the particle were saved by the software.…”

Nanodiamond Relaxometry-Based Detection of Free-Radical Species When Produced in Chemical Reactions in Biologically Relevant Conditions

“…Light is finally detected by an avalanche photodiode (SPCM-AQRF-15-FC) in single photon counting mode. More information on the equipment can be found in an article by Morita et al 27 For our measurements, we excluded obvious aggregates. We also chose particles with counts between 10 6 and 10 7 counts/s and relaxation times between 90 and 300 μs.…”

Not all cells are created equal – endosomal escape in fluorescent nanodiamonds in different cells

“…Recently, this method was applied in cell biology. There nanodiamonds have been utilised for nanoscale temperature measurements[ 23 , 24 ] or to measure free radical generation during stress responses [ 25 ]. For all these applications it is crucial to determine where exactly the nanodiamonds end up.…”