b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”
178 Tissue Engineering and Nanotheranostics
field in the gap between L– and S–AuNPs allows indirect and
sensitive monitoring of the catalytic reaction, which provides ready
extraction of physicochemical parameters for quantitative under
standing of AuNPbased catalysis.143,144
5.3. Localized Surface Plasmon Resonance Imaging in Cells
The distancedependent electromagnetic coupling of nanoparticles
provides a unique approach for realtime monitoring nanoparticles
assembly and subsequent trafficking during nanoparticles ternaliza
tion. Reinhard et al. used this method to investigate the interactions
of negatively charged AuNPs with J774A.1 muring macrophages.^14
They demonstrated that AuNPs uptake is mediated by scavenger
receptors, and this internalization is associated with a time and con
centrationdependent nanoparticles assembling process. Detailed
study showed that both caveolin and clathrindependent endocytosis
domain this uptake process. The clathrindependent endocytosis leads
to nonagglomerated nanoparticles uptake within the cells while
caveolindependent endocytosis induces the formation of compact
nanoparticles clusters. Sokolov et al. applied DFM to track anti
EGFR AuNPs, and found a progressive redshift greater than 100 nm
in the nanoparticle plasmon resonance wavelength over a time period
of 60 min.^145 They demonstrated that changes in the scattering peak
are associated with EGFR trapped by the cell membrane, early
endosomes, and late endosomes. Combining these experiment data
with statistical analysis of RGBchannel, they create a realtime map
of EGFR regulatory states in living cells.
In addition, there are many other works on the determination of
noble nanoparticle interacting with cellular, for example, a micro
scopic method was developed to quantify the number of nanoparticle
and the degree of their aggregation in the cells.146,147 The major
advantage of this method is to eliminate the influence of nanoparticles
binding to the outer surface of the cells. Fan et al. also reported some
work on the interaction between AuNPs and cells, such as the uptake
methods, the transport pathways and the regulation by DNA
nanotechnology.^148
