PolySciTech (www.polyscitech.com) provides a wide
array of biodegradable block copolymers. Recently a publication utilized
PolyVivo AK09 as part of a system for imaging and targeting tumor cells. Read
more: Rapoport, Natalya, Roohi Gupta, Yoo-Shin Kim, and Brian E. O’Neill.
"Polymeric Micelles and nanoemulsions as tumor-targeted drug carriers:
Insight through intravital imaging." Journal of Controlled Release (2015).
http://www.sciencedirect.com/science/article/pii/S0168365915001662
“Abstract:
Intravital imaging of nanoparticle extravasation and tumor accumulation has
revealed, for the first time, detailed features of carrier and drug behavior in
circulation and tissue that suggest new directions for optimization of drug
nanocarriers. Using intravital fluorescent microscopy, the extent of the
extravasation, diffusion in the tissue, internalization by tissue cells, and
uptake by the RES system were studied for polymeric micelles, nanoemulsions,
and nanoemulsion-encapsulated drug. Discrimination of vascular and tissue
compartments in the processes of micelle and nanodroplets extravasation and
tissue accumulation was possible. A simple 1-D continuum model was suggested
that allowed discriminating between various kinetic regimes of nanocarrier (or
released drug) internalization in tumors of various sizes and cell density. The
extravasation and tumor cell internalization occurred much faster for polymeric
micelles than for nanoemulsion droplets. Fast micelle internalization resulted
in the formation of a perivascular fluorescent coating around blood vessels. A
new mechanism of micelle extravasation and internalization was suggested, based
on the fast extravasation and internalization rates of copolymer unimers while
maintaining micelle/unimer equilibrium in the circulation.The data suggested
that to be therapeutically effective, nanoparticles with high internalization
rate should manifest fast diffusion in the tumor tissue in order to avoid
generation of concentration gradients that induce drug resistance. However an
extra-fast diffusion should be avoided as it may result in the flow of
extravasated nanoparticles from the tumor to normal organs, which would
compromise targeting efficiency. The extravasation kinetics were different for
nanodroplets and nanodroplet-encapsulated drug F-PTX suggesting a premature
release of some fraction of the drug from the carrier. In conclusion, the
development of an “ideal” drug carrier should involve the optimization of both
drug retention and carrier diffusion parameters. Keywords: drug delivery;
perfluorocarbon; nanodroplets; micelles; paclitaxel; nanoparticle
extravasation; nanoparticle diffusion; intravital microscopy”
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