Oxidation-Sensitive Polymeric Nanoparticles

Abstract

We have recently demonstrated the possible use of organic polysulfides for the design of oxidation-sensitive colloidal carriers in the form of polymeric vesicles, which are particularly suitable for the encapsulation of hydrosoluble drugs. In the present research we extend our efforts to carriers specifically suitable for hydrophobic molecules. Exploiting the living emulsion polymerization of episulfides, we have produced new cross-linked polysulfide nanoparticles. Here we demonstrate how this process allows the production of stable nanoparticles with a good control over their size and functionality. The nanoparticles showed negligible cytotoxicity on a fibroblast model; furthermore, they exhibited sensitivity to oxidative conditions, which first produce swelling and then solubilize the material.

Exploiting lymphatic transport and complement activation in nanoparticle vaccines

“…As a nanoparticulate platform for antigen delivery, we used Pluronic-stabilized polypropylene sulfide (PPS) nanoparticles 8 .…”

“…Shown is a co-infusion into mouse-tail skin with 100-and 25-nm fluorescently labeled nanoparticles (100-and 25-NPs, respectively) where the 25-NPs enter the dermal lymphatic capillary network much more efficiently than 100-NPs do. (such as those found within the lysosome), and a hydrophilic surface corona of Pluronic, a block copolymer of polyethylene glycol and polypropylene glycol 8 . The Pluronic enables good size control down to B20 nm during inverse emulsion polymerization 8 .…”

“…(such as those found within the lysosome), and a hydrophilic surface corona of Pluronic, a block copolymer of polyethylene glycol and polypropylene glycol 8 . The Pluronic enables good size control down to B20 nm during inverse emulsion polymerization 8 . By selecting the lymph node as our target, we seek to achieve localization of the nanoparticles where dendritic cells exist in high concentrations and where a substantial fraction of dendritic cells are phenotypically and functionally immature 9 and thus able to process new antigen.…”

“…Nanoparticle synthesis. Pluronic-stabilized PPS nanoparticles with diameters of 25 and 100 nm were synthesized by inverse emulsion polymerization as described elsewhere 8 .…”

Physical and Chemical Strategies for Therapeutic Delivery by Using Polymeric Nanoparticles

“…In addition, changes in ionic strength causes a proton sponge effect in certain cationic buffering polymers that can allow the endosome to release encapsulated material. Delivery of drugs using pH-responsive nanoparticles via the endosome and into the cytoplasm Gao et al, 2005;Bae et al, 2007;Cohen et al, 2008Cohen et al, , 2009Lee et al, 2008 Thermal Heat applied external or from physiologically changes De et al, 2008;Rahimi et al, 2008;Peng et al, 2011 Light Externally applied light Suzuki and Tanaka, 1990;Goodwin et al, 2005;Jiang et al, 2006;Fomina et al, 2010 Redox Regions where reactive oxidative and reductive species are abundant (inflammation and tumor sites) Napoli et al, 2004;Rehor et al, 2005;Reddy et al, 2006;Wilson et al, 2010;Mahmoud et al, 2011 Enzyme Regions of high protease expression such as cancerous tissue Olson et al, 2009;Andresen et al, 2010;Whitney et al, 2010;van Duijnhoven et al, 2011;Wong et al, 2011 514 is very effective and in some cases seems also to improve drug resistance . Delivery of nucleic acid therapeutics for gene or siRNA delivery seems to be very promising when delivered using pH-responsive materials.…”