New poly(amidoamine)s containing disulfide linkages in their main chain

Abstract

Novel poly(amidoamine)s (PAAs) containing disulfide linkages regularly arranged along their backbones were synthesized by the stepwise polyaddition of 2-methylpiperazine to N,NЈ-bis(acryloyl)cystamine (BACy1) or N,NЈ-bis(acryloyl)-(L)cystine (BACy2). Both bisacrylamides had, in turn, been obtained by the reaction of acryloyl chloride with the corresponding amines. All the products were characterized with 1 H and 13 C NMR spectroscopy, and the average molecular weights of the polymers were determined by size exclusion chromatography. Both PAAs showed different solubility properties. In particular, PAA-Cy1, derived from BACy1, was sparingly soluble in water, whereas PAA-Cy2, derived from BACy2, was very soluble in aqueous media. The polymerization rates were investigated with 1 H NMR spectroscopy. In both cases, the experimental data were consistent with pseudo-second-order kinetics. The calculated kinetic constants were 5.96 ϫ 10 Ϫ3 and 5.90 ϫ 10 Ϫ2 min Ϫ1 L mol Ϫ1 for the polyaddition of BACy1 and BACy2, respectively. The observed hydrolytic degradation rate of PAA-Cy2 in a pH 7.4 tris(hydroxymethyl)aminomethane (TRIS) buffer was comparable to that of conventional amphoteric PAAs, that is, PAAs containing carboxyl groups in their repeating unit. Degradation experiments carried out in the presence of 2-mercaptoethanol with both PAAs demonstrated that the disulfide groups contained in its repeating units were susceptible to reductive cleavage in the presence of thiols.

A Cleavable‐Polycation Template Method for the Fabrication of Noncrosslinked, Porous Polyelectrolyte Multilayered Films

“…The main-chain structure of 1 is similar to that of the polycation reported by Ferruti and coworkers. [38] The chemical structures of the polymers 1 and 2 are shown in Figure 1. Both 1 and 2 are soluble and stable in PBS (pH 7.4), however, 1 is reductively cleaved into small molecular fragments in PBS containing DTT, whereas 2 is still stable.…”

Dual-degradable disulfide-containing PEI–Pluronic/DNA polyplexes: transfection efficiency and balancing protection and DNA release

“…[34][35][36] The morphology of multiblock PA-PEI-SS/DNA complexes in aqueous solution was examined by TEM at room temperature. The TEM image showed complex aggregates with a diameter of 150-250 nm ( Figure 5).…”

Reducible poly(amido ethylenediamine) for hypoxia-inducible VEGF delivery

“…SS-PAAs are promising due to their: (1) facile synthesis, (2) stability in an aqueous environment for purification, (3) endosomal buffering capacity, (4) small particle formation when complexed with plasmid DNA (pDNA), (5) relative low toxicity and high mediated gene expression compared to PEI, (6) low serum interactions in vitro and (7) the ability to take advantage of the high physiological redox potential leading to better release of genetic material inside the cellular compartment [19][20][21].…”