Phosphonium Polymethacrylates for Short Interfering RNA Delivery: Effect of Polymer and RNA Structural Parameters on Polyplex Assembly and Gene Knockdown

Abstract

(2015) Phosphonium polymethacrylates for siRNA delivery: effect of polymer and RNA structural parameters on polyplex assembly and gene knockdown. Biomacromolecules, 16 (11). pp. 3480-3490. ISSN 1525-7797 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/35894/1/Phosphonium%20Polymethacrylates%20for %20Short%20Interfering%20RNA%20Delivery%20-%20%20Effect%20of%20Polymer %20and%20RNA%20Structural%20Parameters%20on%20Polyplex%20Assembly%20and %20Gene%20Knockdown%20-%20AAM.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the Creative Commons Attribution Non-commercial licence and may be reused according to the conditions of the licence. For more details see: http://creativecommons.org/licenses/by-nc/2.5/ A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. ABSTRACT: Synthetic polymers containing quaternary phosphonium salts are an emerging class of materials for the delivery of oligo/polynucleotides. In this work, cationic phosphonium saltcontaining polymethacrylates -and their corresponding ammonium analogues-were synthesized by RAFT polymerization. Both the nature of the charged heteroatom (N vs. P) and the length of the spacer separating the cationic units along the polymer backbone (oxyethylene vs. trioxyethylene) were systematically varied. Polymers efficiently bound siRNA at N + /P -or P + /Pratios of 2 and above. At a 20:1 ratio, small polyplexes (Rh: 4-15 nm) suitable for cellular uptake were formed that displayed low cytotoxicity. Whilst siRNA polyplexes from both ammonium and phosphonium polymers were efficiently internalised by GFP-expressing 3T3 cells, no knockdown of GFP expression was observed. However, 65% Survivin gene knockdown was observed when short interfering RNA (siRNA) was replaced with novel, multimerised long interfering liRNA 2 (liRNA) in HeLa cells, demonstrating the importance of RNA macromolecular architecture on RNA-mediated gene silencing.

Efficient Binding, Protection, and Self-Release of dsRNA in Soil by Linear and Star Cationic Polymers

“…Cationic polymers have been extensively employed to protect RNA and DNA from degradation with numerous natural and synthetic examples , including amine functionalized polysaccharides, poly­( l -lysine), poly­(amidoamines), poly­(amino- co -ester)­s, , poly­((dimethylamino)­ethyl methacrylate) (PDMAEMA), and poly­(ethylene imines) . Although these polymers can efficiently bind to RNA they are however incapable of release due to the very high positive charge density.…”

Interactions in DNA Condensation: An Important Factor for Improving the Efficacy of Gene Transfection

“…Increasing the affinity between cationic polymer and DNA without reducing the release of DNA after endocytosis can not only achieve effective gene delivery with less cationic polymer but also increase the stability of the complex in the body fluid environment with increasing transfection. 34,35 As mentioned above, because the positive charge based on high electronegativity nitrogen is not strong enough to bind DNA, the researchers have developed other cations with more positive charged cation like phosphorus, 33,36,37 arsenic, 38 and sulfur. 39,40 These atoms, structurally a larger and less electronegative atom than nitrogen, could form larger cations with different electron density distributions compared with ammonium cations.…”

“…As mentioned above, because the positive charge based on high electronegativity nitrogen is not strong enough to bind DNA, the researchers have developed other cations with more positive charged cation like phosphorus, ,, arsenic, and sulfur. , These atoms, structurally a larger and less electronegative atom than nitrogen, could form larger cations with different electron density distributions compared with ammonium cations. And the results of ab initio calculations of the charge distribution on the cationic atom and the surrounding carbons have shown that the nitrogen atom had a negative charge with a positive charge on the adjacent carbons while phosphorus and sulfur atoms had a positive charge with a negative charge on the adjacent carbons (as shown in Table ).…”

Synthesis and Applications of Protein/Peptide-Polymer Conjugates

“…Examples of natural ligands include cofactors for enzyme reconstitution, sugars and biotin that have high affinity interactions with lectins and streptavidin respectively. Alternatively, synthetic ligands have been designed that exploit electrostatic interactions, metal‐ligand affinity and host guest interactions to couple proteins/peptides and polymers. Finally, proteins/peptides can be incorporated into polymer gel matrices, either as non‐covalent cross‐linking groups (e.g.…”