  Tracking the dynamics of fluorescent nanoparticles during embryonic
development allows insights into the physical state of the embryo and,
potentially, molecular processes governing developmental mechanisms. In this
work, we investigate the motion of individual fluorescent nanodiamonds
micro-injected into Drosophila melanogaster embryos prior to cellularisation.
Fluorescence correlation spectroscopy and wide-field imaging techniques are
applied to individual fluorescent nanodiamonds in blastoderm cells during stage
5 of development to a depth of ~40 \mu m. The majority of nanodiamonds in the
blastoderm cells during cellularisation exhibit free diffusion with an average
diffusion coefficient of (6 $\pm$ 3) x 10$^{-3}$ \mu m$^2$/s, (mean $\pm$ SD).
Driven motion in the blastoderm cells was also observed with an average
velocity of 0.13 $\pm$ 0.10 \mu m/s (mean $\pm$ SD) \mu m/s and an average
applied force of 0.07 $\pm$ 0.05 pN (mean $\pm$ SD). Nanodiamonds in the
periplasm between the nuclei and yolk were also found to undergo free diffusion
with a significantly larger diffusion coefficient of (63 $\pm$ 35) x10$^{-3}$
\mu m$^2$/s (mean $\pm$ SD). Driven motion in this region exhibited similar
average velocities and applied forces compared to the blastoderm cells
indicating the transport dynamics in the two cytoplasmic regions are analogous.
