NanoSight, leading manufacturers of unique
nanoparticle characterization technology, reports on the work of Dr Seow Yiqi
at SCEI, Singapore where they apply Nanoparticle Tracking Analysis (NTA) to
characterize exosomes for use in delivering therapeutic moieties to specific
tissues in vivo.
The Molecular Engineering Laboratory was established in 2009 by Nobel Laureate
Dr Sydney Brenner as a multi-disciplinary laboratory where diverse expertise
from different realms of science could come together to develop novel
technologies. Post-doctoral fellows in the laboratory undertake a wide variety
of research ranging from organic fluorophore development to characterization of
marine biomaterials with unique physical properties to genetic therapies.
Dr Seow Yiqi is working to use exosomes (nanoparticles secreted by cells of
~100nm in size) to deliver therapeutic moieties to specific tissues
in vivo. This is work
that follows on from his DPhil studies at the University of Oxford in Professor
Matthew Wood's group. Describing his work, he said "I used targeted
exosomes loaded with siRNA to effect knockdown in the brain after intravenous
injection of these exosomes. The development of 'self' delivery vehicles, such
as patient-derived exosomes, may be a good first step towards gene/drug therapy
that requires repeated delivery over a period of years or decades. Towards this
aim, using the NanoSight system has proved to be invaluable in providing size
and concentration measurement for each exosome purification. This data allows
me to check the quality and purity of the preparation as well as to look at the
physical effects of my surface modifications and loading protocols on the
physical characteristics of exosomes."
Other than NTA, he had used dynamic light scattering (DLS) for bulk
measurement, and transmission electron microscopy using negative staining with
phosphotungstanic acid for sizing. DLS was useful if the purification was pure
and the sample being measured was relatively homogenous, but more often than
not, the population purified tended to be polydisperse with nanoparticles of
varying sizes in the same preparation. That biased the DLS measurements and it
was difficult to get reproducible results with the system. In contrast, the TEM
was accurate and precise, but the preparation was arduous and time-consuming
and the results are a very small representation of the bulk, so it was not
useful in working out concentration or size distribution. Concluding, he says,
"Using Nanoparticle Tracking Analysis overcame these issues perfectly for
my work. Measurements were rapid and by counting particle by particle, the true
polydisperse nature of the samples was reported."
To find out about the company and to learn more about particle characterization
using NanoSight's unique nanoparticle tracking analysis solutions, visit
www.nanosight.com
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newsletter.
About NanoSightNanoSight delivers the
world's most versatile and proven multi-parameter nanoparticle analysis in a
single instrument.
NanoSight's
"Nanoparticle Tracking Analysis" (NTA) detects and visualizes
populations of nanoparticles in liquids down to 10 nm, dependent on material,
and measures the size of each particle from direct observations of diffusion.
Additionally, NanoSight measures concentration and a fluorescence mode
differentiates suitably-labelled particles within complex background
suspensions. Zeta potential measurements are similarly particle-specific. It is
this particle-by-particle methodology that takes NTA beyond traditional light
scattering and other ensemble techniques in providing high-resolution particle
size distributions and validates data with information-rich video files of the
particles moving under Brownian motion.
This simultaneous
multiparameter characterization matches the demands of complex biological
systems, hence its wide application in development of drug delivery systems, of
viral vaccines, and in nanotoxicology. This real-time data gives insight into
the kinetics of protein aggregation and other time-dependent phenomena in a
qualitative and quantitative manner. NanoSight has a growing role in
biodiagnostics, being proven in detection and speciation of nanovesicles
(exosomes) and microvesicles.
NanoSight has installed
approaching 500 systems worldwide with users including BASF, GlaxoSmithKline,
Merck, Novartis, Pfizer, Proctor and Gamble, Roche and Unilever together with
the most eminent universities and research institutes. NanoSight's technology
is validated by 450+ third party papers citing NanoSight results and by the
ASTM Standard E2834, consolidating NanoSight's leadership position in
nanoparticle characterization.