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Tuning silica nanoparticles for cell specific biotargeting Malvern’s Zetasizer
Nano characterizes all surface modifications
9 June 2009: Malvern, UK: Researchers from Abo Akademi University and the
University of Turku in Finland have discovered that the stability of
functionalised nanoparticles is crucially dependent on all functional groups
present on the surface. Using the sensitive nanoscale particle sizing and zeta
potential measurement capabilities of a Zetasizer Nano from Malvern Instruments,
they showed that poly(ethylene imine) (PEI) functionalised silica particles made
promising candidates for bioapplications. This research has now led to the
development of a selective nanoparticulate system for cancer cell targeting.
One of the key aims in biomedical science is to develop applications that can
target and deliver drug to specific cell populations. Porous, non-toxic silica
based structures have potential as biocompatible vehicles for intracellular
delivery of an active ingredient. However, any modification to the original
particle structure, such as the addition of an imaging agent, surface coating or
a targeting agent, changes both its size and surface charge. This leads to
changes in the stability of the particulate system.
Using both particle sizing using dynamic light scattering (DLS) and zeta
potential measurements with a Zetasizer Nano, the Finnish research team showed
both direct and indirect effects on the suspension stability of functionalised
silica particles as a result of surface modification. These results were
published in the Journal of Nanomaterials in 2008. The team then went on,
publishing results in ACS Nano in 2009 that used similar techniques to develop a
multifunctional nanodevice for cancer therapy that demonstrated remarkably good
cell specificity.
The size, stability and cell specificity of functionalised nanoparticles for
targeted drug delivery is crucially dependent on each surface modification as
well as the overall surface charge. Besides the fact that surface charge along
with particle size are directly decisive for a nanoparticles’ biodistribution,
other highly critical factors, such as cytotoxicity and the efficiency of
cellular uptake, are associated with nanoparticle size. While the technique of
dynamic light scattering (DLS) is ideally suited for the determination of
particle size, zeta potential measurements indicate the repulsive force that is
present and can be used to predict the long-term stability of the product. By
enabling both types of measurements, with the sensitivity and resolution
required to define nanoscale changes, Malvern’s Zetasizer is the ideal solution
for biomedical scientists.
www.malvern.com/zetasizer
Malvern, Malvern Instruments and Zetasizer are registered trademarks of Malvern
Instruments Ltd
End
High resolution image attached or available from Trish Appleton,
Kapler Communications
trish@kapleronline.com Ref: MAL/JOB/1762
CAPTION: Mesoporous silica nanoparticles, seen as orange, inside a HeLa
cancer cell seen as green. For more details see L. Bergman et al. J. Nanomater.
doi:10.1155/2008/712514 and J.M. Rosenhom et al. ACS Nano 3 (2009) 197
About Malvern Instruments
Malvern Instruments provides a range of complementary materials
characterization tools that deliver inter-related measurements reflecting the
complexities of particulates and disperse systems, nanomaterials and
macromolecules. Analytical instruments from Malvern are used in the
characterization of a wide variety of materials, from industrial bulk powders to
nanomaterials and delicate macromolecules. A broad portfolio of innovative
technologies is combined with intelligent, user-friendly software. These systems
deliver industrially relevant data enabling our customers to make the connection
between micro (such as particle size) and macro (bulk) material properties (rheology)
and chemical composition (chemical imaging).
Particle size, particle shape, zeta potential, molecular weight, chemical
composition and rheological properties measurements are now joined by advanced
chromatography solutions (GPC/SEC), extending Malvern’s technologies for protein
molecular weight, size and aggregation measurements, and synthetic polymer
molecular weight and distribution. The company’s laboratory, at-line, on-line
and in-line solutions are proven in sectors as diverse as cement production and
pharmaceutical drug discovery.
Headquartered in Malvern, UK, Malvern Instruments has subsidiary organizations
in all major European markets, North America, China, Korea and Japan, a joint
venture in India, a global distributor network and applications laboratories
around the world. www.malvern.com
For press information, please contact:
Trish Appleton, Kapler Communications
Knowledge Centre, Wyboston Lakes, Great North Road,
Wyboston, Bedfordshire, MK44 3BY, UK
Tel: +44 (0)1480 479280; Fax: +44 (0)1480 470343
trish@kapleronline.com
USA contact:
Marisa Fraser, Malvern Instruments Inc.
117 Flanders Road, Westborough, MA 01581-1042 USA
Tel: +1 508 768 6400 Fax: +1 508 768 6403
marisa.fraser@malvern.com
Please send sales enquiries to:
Alison Vines, Malvern Instruments Ltd
Enigma Business Park, Grovewood Road, Malvern, Worcestershire WR14 1XZ UK
Tel: +44 (0) 1684 892456; Fax: +44 (0) 1684 892789
salesinfo@malvern.com
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