Block Ionomer Complexes Consisting of SiRNA and RAFT-synthesized Hydrophilic--cationic Copolymers II: The Influence of Cationic Block Charge Density on Gene Suppression

Overview

Journal Polym Chem

Publisher Royal Society of Chemistry

Date 2017 Feb 28

PMID 28239425

Citations 4

Authors

Keith H Parsons

Andrew C Holley

Gabrielle A Munn

Alex S Flynt

Charles L McCormick

Affiliations

Soon will be listed here.

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--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.

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References

Lee H, Son S, Sharma R, Won Y . A discussion of the pH-dependent protonation behaviors of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(ethylenimine-ran-2-ethyl-2-oxazoline) (P(EI-r-EOz)). J Phys Chem B. 2011; 115(5):844-60. DOI: 10.1021/jp109151s. View

Merdan T, Kunath K, Fischer D, Kopecek J, Kissel T . Intracellular processing of poly(ethylene imine)/ribozyme complexes can be observed in living cells by using confocal laser scanning microscopy and inhibitor experiments. Pharm Res. 2002; 19(2):140-6. DOI: 10.1023/a:1014212630566. View

Fischer D, Li Y, Ahlemeyer B, Krieglstein J, Kissel T . In vitro cytotoxicity testing of polycations: influence of polymer structure on cell viability and hemolysis. Biomaterials. 2003; 24(7):1121-31. DOI: 10.1016/s0142-9612(02)00445-3. View

Gebhart C, Kabanov A . Evaluation of polyplexes as gene transfer agents. J Control Release. 2001; 73(2-3):401-16. DOI: 10.1016/s0168-3659(01)00357-1. View

Fire A, Xu S, Montgomery M, Kostas S, Driver S, Mello C . Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature. 1998; 391(6669):806-11. DOI: 10.1038/35888. View

Holley A, Ray J, Wan W, Savin D, McCormick C . Endolytic, pH-responsive HPMA-b-(L-Glu) copolymers synthesized via sequential aqueous RAFT and ring-opening polymerizations. Biomacromolecules. 2013; 14(10):3793-9. DOI: 10.1021/bm401205y. View

Kopecek J . Controlled biodegradability of polymers--a key to drug delivery systems. Biomaterials. 1984; 5(1):19-25. DOI: 10.1016/0142-9612(84)90062-0. View

Bishop G, Chaires J . Characterization of DNA structures by circular dichroism. Curr Protoc Nucleic Acid Chem. 2008; Chapter 7:7.11.1-7.11.8. DOI: 10.1002/0471142700.nc0711s11. View

Convertine A, Benoit D, Duvall C, Hoffman A, Stayton P . Development of a novel endosomolytic diblock copolymer for siRNA delivery. J Control Release. 2008; 133(3):221-9. PMC: 3110267. DOI: 10.1016/j.jconrel.2008.10.004. View

10.

Dorsett Y, Tuschl T . siRNAs: applications in functional genomics and potential as therapeutics. Nat Rev Drug Discov. 2004; 3(4):318-29. DOI: 10.1038/nrd1345. View

11.

Kirkland-York S, Zhang Y, Smith A, York A, Huang F, McCormick C . Tailored design of Au nanoparticle-siRNA carriers utilizing reversible addition-fragmentation chain transfer polymers. Biomacromolecules. 2010; 11(4):1052-9. DOI: 10.1021/bm100020x. View

12.

Elbashir S, Harborth J, Lendeckel W, Yalcin A, Weber K, Tuschl T . Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature. 2001; 411(6836):494-8. DOI: 10.1038/35078107. View

13.

York A, Zhang Y, Holley A, Guo Y, Huang F, McCormick C . Facile synthesis of multivalent folate-block copolymer conjugates via aqueous RAFT polymerization: targeted delivery of siRNA and subsequent gene suppression. Biomacromolecules. 2009; 10(4):936-43. PMC: 2723843. DOI: 10.1021/bm8014768. View

14.

Sarisozen C, Salzano G, Torchilin V . Recent advances in siRNA delivery. Biomol Concepts. 2015; 6(5-6):321-41. DOI: 10.1515/bmc-2015-0019. View

15.

Treat N, Smith D, Teng C, Flores J, Abel B, York A . Guanidine-Containing Methacrylamide (Co)polymers via aRAFT: Toward a Cell Penetrating Peptide Mimic(). ACS Macro Lett. 2012; 1(1):100-104. PMC: 3359019. DOI: 10.1021/mz200012p. View

16.

Allen M, Green M, Getaneh H, Miller K, Long T . Tailoring charge density and hydrogen bonding of imidazolium copolymers for efficient gene delivery. Biomacromolecules. 2011; 12(6):2243-50. DOI: 10.1021/bm2003303. View

17.

Deshpande M, Davies M, Garnett M, Williams P, Armitage D, Bailey L . The effect of poly(ethylene glycol) molecular architecture on cellular interaction and uptake of DNA complexes. J Control Release. 2004; 97(1):143-56. DOI: 10.1016/j.jconrel.2004.02.019. View

18.

Park T, Jeong J, Kim S . Current status of polymeric gene delivery systems. Adv Drug Deliv Rev. 2006; 58(4):467-86. DOI: 10.1016/j.addr.2006.03.007. View

19.

Song Y, Wang H, Zeng X, Sun Y, Zhang X, Zhou J . Effect of molecular weight and degree of substitution of quaternized cellulose on the efficiency of gene transfection. Bioconjug Chem. 2010; 21(7):1271-9. DOI: 10.1021/bc100068f. View

20.

MacLaughlin F, Mumper R, Wang J, Tagliaferri J, Gill I, Hinchcliffe M . Chitosan and depolymerized chitosan oligomers as condensing carriers for in vivo plasmid delivery. J Control Release. 1998; 56(1-3):259-72. DOI: 10.1016/s0168-3659(98)00097-2. View