Quaternized Poly[3,5-bis(dimethylaminomethylene)hydroxystyrene]/DNA Complexes: Structure Formation as a Function of Solution Ionic Strength

Abstract

The formation of complexes between the cationic polyelectrolyte poly[3,5-bis(dimethylaminomethylene)hydroxystyrene] (Q-N-PHOS), bearing two cationic sites per repeating unit, and DNA molecules in aqueous solutions is investigated at pH 7 and at various salt (NaCl) concentrations and DNA/polymer ratios. The structural characteristics of the polyplexes at different DNA/polymer ratios were characterized in terms of mass, size, and charge using static, dynamic, and electrophoretic light scattering and fluorescence spectroscopy. The results indicate that the complexes have a loose spherical morphology with size in the range of 45-100 nm depending on polymer to DNA ratio and ionic strength of the solution. Most interestingly, it is found that the polyplexes' response to changes in the ionic strength of the surrounding solution after complexation depends strongly on the initial solution ionic strength during complex formation. This also points to differences in the nanostructures of polyplexes formed at different ionic strengths.

Small nanosized poly(vinyl benzyl trimethylammonium chloride) based polyplexes for siRNA delivery

“…At a heparin concentration of 200 mg/mL and higher, siRNA was completely released from PP4/ PP2 polyplexes, whereas only part of siRNA released from the PVTC/siRNA polyplexes. This heparin competition study demonstrates that strong electrostatic interactions occur between the quaternary amine groups of the polymers and the phosphate groups of siRNA, which is accordance with previous studies (Delisavva et al, 2013;Varkouhi et al, 2012).…”

“…Apart from this, several studies have indicated that the simple conversion of primary into quaternary amines or the use of polymers already containing quaternary amine groups could enhance the polymer-siRNA binding strength and lead to the particles that are more colloidally stable in physiological fluids. (Amar-Lewis et al, 2014;Arigita et al, 1999;Delisavva et al, 2013;Engelberth et al, 2015;Patil et al, 2008;Tamura et al, 2010).…”

Microscopic insight into the DNA condensation process of a zwitterion‐functionalized polycation

“…The structure and morphology of polycation/DNA nanoparticles could give much information concerning the polyplex formation process. The morphologies including toroids, rods and loose spherical morphology have been observed . The size of the DNA condensates and their efficacy varied with the structural geometry of the polycation, polymer to DNA ratio and ionic strength of the solution .…”

“…The morphologies including toroids, rods and loose spherical morphology have been observed . The size of the DNA condensates and their efficacy varied with the structural geometry of the polycation, polymer to DNA ratio and ionic strength of the solution . However, the morphology evolution has not been studied to illustrate the DNA condensation of polyzwitterion.…”

“…[33][34][35] The size of the DNA condensates and their efficacy varied with the structural geometry of the polycation, [36] polymer to DNA ratio and ionic strength of the solution. [34] However, the morphology evolution has not been studied to illustrate the DNA condensation of polyzwitterion. And there has not been a fundamental understanding of the microscopic differences in the process of DNA condensation among PSBMA-functionalized polycations, the pristine polycation, and the PSBMA homopolymer.…”