title: Block ionomer complexes consisting of siRNA andaRAFT-synthesized hydrophilic-block-cationic copolymers II: The influence of cationic block charge density on gene suppression.
abstract: Block ionomer complex (BIC)-siRNA interactions and effectiveness in cell transfection are reported. Aqueous RAFT polymerization was used to prepare a series of hydrophilic-block-cationic copolymers in which the cationic block statistically incorporates increasing amounts of neutral, hydrophilic monomer such that the number of cationic groups remains unchanged but the cationic charge density is diluted along the polymer backbone. Reduced charge density decreases the electrostatic binding strength between copolymers and siRNA with the goal of improving siRNA release after targeted cellular delivery. However, lower binding strength resulted in decreased transfection and RNA interference pathway activation, leading to reduced gene knockdown. Enzymatic siRNA degradation studies with BICs indicated lowered binding strength increases susceptibility to RNases, which is the likely cause for poor gene knockdown.
authors.affiliation: Department of Polymer Science and Engineering, The University of Southern, Mississippi, Hattiesburg, MS 39406, USA.
authors.forename: Keith H
authors.initials: KH
authors.lastname: Parsons
authors.affiliation: Department of Polymer Science and Engineering, The University of Southern, Mississippi, Hattiesburg, MS 39406, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Holley
authors.affiliation: Department of Polymer Science and Engineering, The University of Southern, Mississippi, Hattiesburg, MS 39406, USA.
authors.forename: Gabrielle A
authors.initials: GA
authors.lastname: Munn
authors.affiliation: Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406, USA.
authors.forename: Alex S
authors.initials: AS
authors.lastname: Flynt
authors.affiliation: Department of Polymer Science and Engineering, The University of Southern, Mississippi, Hattiesburg, MS 39406, USA; Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, MS 39406, USA.
authors.forename: Charles L
authors.initials: CL
authors.lastname: McCormick