PolySciTech
Division of Akina, Inc. (www.polyscitech.com)
provides a wide array of polymers including PLGA and related activated
precursors such as PLGA-NHS. These kinds of polymers have been utilized to
develop a theranostic targeted nanoparticle. Theranostics is a relatively new
approach to cancer in which the targeting strategy serves to both diagnose the
cancer (by fluorescence or radio-opacity) as well as treat cancer (by delivery
of chemotherapeutic agents). Researchers in Belgium recently developed such
targeted nanoparticles by using two different targeting strategies. The first
of which was to conjugate RGD labelling peptide onto the exterior of the PLGA
nanoparticle so that it can preferentially bind to cancer cells by targeting
the αvβ3 integrin, an integrin involved in angiogenesis that is overexpressed
on cancer cells. Additionally the particles were loaded with super-paramagnetic
iron oxide (SPIO) which renders the particles magnetic. By simply placing a
magnet near the tumor, the particles can be attracted to the magnet. SPIO
serves another diagnostic purpose in that it serves as a MRI contrast agent
allowing the tumor to be visualized by this technique. The particles were also
loaded with chemotherapeutic paclitaxel and the system analyzed extensively.
You can read about this work here: Danhier, Fabienne, Pierre Danhier, Nathalie
Schleich, Chrystelle Po, Sophie Laurent, Pierre Sibret, Christine Jeroˆme,
Vincent Poucelle, Bernard Gallez, and Veronique Preat. "Tumor Targeting by
RGD-Grafted PLGA-Based Nanotheranostics Loaded with Paclitaxel and
Superparamagnetic Iron Oxides." (2015). http://link.springer.com/protocol/10.1007/7653_2015_43
“Abstract: Theranostic
nanoparticles have the potential to revolutionize cancer diagnosis and therapy.
Many groups have demonstrated differential levels of tumor growth between
tumors treated by targeted or untargeted nanoparticles; however, only few have
shown in vivo efficacy in both therapeutic and diagnostic approach. Herein, we
first develop and characterize dual-paclitaxel (PTX)/superparamagnetic iron
oxide (SPIO)-loaded PLGA-based nanoparticles grafted with the RGD peptide, for
a theranostic purpose. Second, we compare in vivo different strategies in terms
of targeting capabilities: (1) passive targeting via the EPR effect, (2) active
targeting of αvβ3 integrin via RGD grafting, (3) magnetic guidance via a magnet
placed on the tumor, and (4) the combination of the magnetic guidance and the
active targeting of αvβ3 integrin. In this chapter, we present the general
flowchart applied for this project: (1) the polymer and SPIO synthesis, (2) the
physicochemical characterization of the nanoparticles, (3) the magnetic properties
of the nanoparticles, and (4) the in vivo evaluation of the nanoparticles for
their therapeutic and diagnosis purposes. We employ the electron spin resonance
spectroscopy and magnetic resonance imaging to both quantify and visualize the
accumulation of theranostic nanoparticles into the tumors. Keywords: PLGA-nanoparticles
SPIO Paclitaxel Cancer therapy Magnetic resonance imaging Tumor targeting
Nanotheranostic”
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