Polymeric redox-responsive delivery systems bearing ammonium salts cross-linked via disulfides

Abstract

SummaryA redox-responsive polycationic system was synthesized via copolymerization of N,N-diethylacrylamide (DEAAm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). N,N’-bis(4-chlorobutanoyl)cystamine was used as disulfide-containing cross-linker to form networks by the quaternization of tertiary amine groups. The insoluble cationic hydrogels become soluble by reduction of disulfide to mercaptanes by use of dithiothreitol (DTT), tris(2-carboxyethyl)phosphine (TCEP) or cysteamine, respectively. The soluble polymeric system can be cross-linked again by using oxygen or hydrogen peroxide under basic conditions. The redox-responsive polymer networks can be used for molecular inclusion and controlled release. As an example, phenolphthalein, methylene blue and reactive orange 16 were included into the network. After treatment with DTT a release of the dye could be recognized. Physical properties of the cross-linked materials, e.g., glass transition temperature (T g), swelling behavior and cloud points (T c) were investigated. Redox-responsive behavior was further analyzed by rheological measurements.

A Redox-Responsive Supramolecular Hydrogel for Controllable Dye Release

“…On considering biocompatibility, 1,4‐dithio‐ dl ‐threitol (DTT), glutathione tripeptide (γ‐glutamyl‐cysteinyl‐glycine, GSH), and tris(2‐carboxyethyl) phosphine (TCEP) are used as the most common disulfide‐cleaving agents . As a cellular reducing agent, GSH is a tripeptide cysteine with pendant sulfhydryl (SH) groups in the cytosol and nuclei.…”

Photoacoustic Imaging Quantifies Drug Release from Nanocarriers via Redox Chemistry of Dye‐Labeled Cargo

“…DTT reduces the PTX‐MB to PTX‐LMB in the chloroform medium and then is solubilized in aqueous medium. DTT can also be removed completely after reduction and encapsulation of PTX‐MB in PLGA NPs because DTT has higher solubility in water (50 mg mL −1 ) than in chloroform (10 mg mL −1 ) . Thus, DTT can be easily removed during particle synthesis and washing.…”

Inversion of Supramolecular Chirality by Sonication-Induced Organogelation

“…The viscoelastic behavior of the organogels formed by peptides 1, 2 , and 3 were examined by rheological studies. The shear stress-sweep experiments were performed to evaluate the mechanical strength of the peptide-based organogels in toluene 44 . Figure 4 shows a dependence of the dynamic storage modulus (G′) and the loss modulus (G″) on the shear stress for both organogels formed by peptides 1 and 2 (3.0 wt%) at 25°C.…”