Interactions between PEI and biological polyanions and the ability of glycosaminoglycans in destabilizing PEI/peGFP-C3 polyplexes for genetic material release.

The lack of understanding of polyplexes stability and their dissociation mechanisms, allowing the release of DNA, is currently a major limitation in non-viral gene delivery. One proposed mechanism for DNA-based polyplexes dissociation is based on the electrostatic interactions between polycations and biological polyanions, such as glycosaminoglycans (GAGs). This work aimed at investigating whether GAGs such as heparin, chondroitin sulphate and hyaluronic acid promote the dissociation of PEI/DNA polyplexes.

Star-Like Polypeptides as Simplified Analogues of Horseradish Peroxidase (HRP) Metalloenzymes.

Peroxidases, like horseradish peroxidase (HRP), are heme metalloenzymes that are powerful biocatalysts for various oxidation reactions. By using simple grafting-from approach, ring-opening polymerization (ROP), and manganese porphyrins, star-shaped polypeptides analogues of HRP capable of catalyzing oxidation reactions with HO is successfully prepared. Like their protein model, these simplified analogues show interesting Michaelis-Menten constant (K) in the mM range for the oxidant.

Synthesis, characterization and stability of crosslinked chitosan-maltodextrin pH-sensitive nanogels.

Polysaccharide-based nanogels offer a wide range of chemical compositions and are of great interest due to their biodegradability, biocompatibility, non-toxicity, and their ability to display pH, temperature, or enzymatic response. In this work, we synthesized monodisperse and tunable pH-sensitive nanogels by crosslinking, through reductive amination, chitosan and partially oxidized maltodextrins, by keeping the concentration of chitosan close to its overlap concentration, i.e.

Structural Behavior of Amphiphilic Triblock Copolymer P104/Water System.

A detailed study of the different structural transitions of the triblock copolymer PEO-PPO-PEO (P104) in water, in the dilute and semi-dilute regions, is addressed here as a function of temperature and P104 concentration (C) by mean of complimentary methods: viscosimetry, densimetry, dynamic light scattering, turbidimetry, polarized microscopy, and rheometry. The hydration profile was calculated through density and sound velocity measurements. It was possible to identify the regions where monomers exist, spherical micelle formation, elongated cylindrical micelles formation, clouding points, and liquid crystalline behavior.