PolySciTech
division of Akina, Inc. (www.polyscitech.com)
provides a wide-array of biodegradable polymers including fluorescently
endcapped polymers in the PolyVivo AV*** series. The dye’s conjugated to these
polymers absorb a certain wavelength of light and subsequently emit a different
wavelength of light allowing for them to be imaged in a manner which eliminates
surrounding tissues or other components by applying sharp-cut wavelength
filters to the provided light-source and the observation platform (eye piece or
camera). A common process simply referred to as fluorescence microscopy. The
advantage of these is that nanoparticles or other structures formed using these
systems can be imaged and tracked using fluorescence microscopy. Recently
PolyVivo AV008 (PLGA-FPR648 MW ~20,000; Abs: 648 nm /Em: 672 nm) was used to
track insulin loaded nanoparticles and their penetration into model intestinal
cells as part of research to develop an oral (as opposed to the current injection-based
systems) insulin delivery system. This system holds the promise for a
less-painful treatment option for diabetes. Read more about this exciting
research here: Sheng, Jianyong, Huining He, Limei Han, Jing Qin, Sunhui Chen,
Ge Ru, Ruixiang Li, Pei Yang, Jianxin Wang, and Victor C. Yang. "Enhancing
insulin oral absorption by using mucoadhesive nanoparticles loaded with
LMWP-linked insulin conjugates." Journal of Controlled Release (2016). http://www.sciencedirect.com/science/article/pii/S0168365916302784
“Abstract: Although
significant progress has been made, effective oral delivery of protein drugs
such as insulin by nanoparticle-based carrier systems still faces certain
formidable challenges. Considerable amount of protein drug is released from the
nanoparticles (NPs) in the gastrointestinal (GI) tract. Because of their low
permeability through the intestinal mucosa, the released protein would be soon
degraded by the large amount of proteases in the GI tract. Herein, we report an
oral insulin delivery system that can overcome the above-mentioned problems by
mucoadhesive NPs (MNPs) loaded with cell penetrating peptide-linked insulin
conjugates. On one hand, after conjugation with low molecular weight protamine
(LMWP), a cell penetrating peptide (CPP), insulin showed greatly improved
permeability through intestinal mucus layer and epithelia. On the other hand,
the mucoadhesive N-trimethyl chitosan chloride-coated PLGA nanoparticles (MNPs)
that were loaded with conjugates enhanced the retention in the intestinal mucus
layer. By adopting this delivery strategy, the LMWP-insulin conjugates released
from NPs could be deprived from enzymatic degradation, due to the short
distance in reaching the epithelia and the high permeation of the conjugates
through epithelia. The oral delivery system of insulin designed by us showed a
long-lasting hypoglycemia effect with a faster onset in diabetic rats, with an
oral insulin pharmacological availability being 17.98 ± 5.61% relative to
subcutaneously injected insulin solution, as well as a 2-fold higher
improvement over that by MNPs loaded with native insulin. Our results suggested
that conjugation with CPP followed by encapsulation in MNPs provides an
effective strategy for oral delivery of macromolecular therapeutics. Keywords: Nanoparticles;
Cell-penetrating peptide; Low molecular weight protamine; Insulin; Oral
delivery; Mucoadhesion”
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