Corona-Stabilized Interpolyelectrolyte Complexes of SiRNA with Nonimmunogenic, Hydrophilic/Cationic Block Copolymers Prepared by Aqueous RAFT Polymerization
The complexation of small interfering ribonucleic acid (siRNA) with a series of specifically designed block copolymers consisting of the hydrophilic, nonimmunogenic monomer N-(2-hydroxypropyl)methacrylamide (HPMA) and the cationic monomer N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA) has been investigated for potential siRNA stabilization and delivery applications. Specific compositions of poly(HPMA-b-DMAPMA) copolymers were synthesized via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization and characterized using aqueous size exclusion chromatography with multiangle laser light scattering (SEC-MALLS) and 1H NMR spectroscopy. The degree of soluble complex formation between a model siRNA and the polymers was determined by centrifugal membrane filtration experiments and quantitated by scintillation counting of 32P ATP-labeled siRNA to determine complex solubility and to estimate the degree of complexation relative to cationic and neutral block lengths. Dynamic and static light scattering methods were employed to determine the hydrodynamic radii, molecular weights, and second virial coefficients of the complexes and to demonstrate their unimodal size distributions. In vitro enzymatic degradation studies of selected siRNA/block copolymer complexes were conducted to demonstrate the enhanced stability of the siRNA/poly(HPMA-b-DMAPMA) complexes. Furthermore, the siRNA/polymer complexes dissociate slowly under gel electrophoresis conditions. Therefore, the siRNA/polymer complexes demonstrate some highly desirable properties for potential applications in therapeutic siRNA stabilization and delivery.
C. W. Scales et al., "Corona-Stabilized Interpolyelectrolyte Complexes of SiRNA with Nonimmunogenic, Hydrophilic/Cationic Block Copolymers Prepared by Aqueous RAFT Polymerization," Macromolecules, vol. 39, no. 20, pp. 6871-6881, American Chemical Society (ACS), Oct 2006.
The definitive version is available at https://doi.org/10.1021/ma061453c
Materials Science and Engineering
Keywords and Phrases
Enzymatic degradation; Gel electrophoresis; Neutral block lengths; SiRNA stabilization, Complexation; Electrophoresis; Molecular weight; Monomers; Polyelectrolytes; Polymerization; RNA, Block copolymers
International Standard Serial Number (ISSN)
Article - Journal
© 2006 American Chemical Society (ACS), All rights reserved.
01 Oct 2006