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Updated: Aug 24, 2026

Preparation of Neutrally-charged, pH-responsive Polymeric Nanoparticles for Cytosolic siRNA Delivery
Published on: May 2, 2019
Preparation and characterization of water-soluble pH-sensitive nanocarriers for drug delivery
M-H Dufresne1, D Le Garrec, V Sant
1Canada Research Chair in Drug Delivery, Faculty of Pharmacy, University of Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Que., Canada H3C 3J7.
Abstract:
pH-sensitive drug delivery systems can be engineered to release their contents or change their physicochemical properties in response to variations in the acidity of the surroundings. The present work describes the preparation and characterization of novel polymeric micelles (PM) composed of amphiphilic pH-responsive poly(N-isopropylacrylamide) (PNIPAM) or poly(alkyl(meth)acrylate) derivatives. On one hand, acidification of the PNIPAM copolymers induces a coil-to-globule transition that can be exploited to destabilize the intracellular vesicle membranes. In this work, PNIPAM-based PM were loaded with either doxorubicin or aluminium chloride phthalocyanine and their cytotoxicity was assessed in murine tumoral models. On the other hand, poly(alkyl(meth)acrylate) copolymers can be designed to interact with either hydrophobic drugs or polyions and release their cargo upon an increase in pH.
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