UNCORRECTED PROOFS Cell Biology International ISSN 1065-6995 doi: 10.1002/cbin.10381 MINI-REVIEW DMAEM-based cationic polymers as novel carriers for DNA delivery into cells Iryna V. Tanasienko 1 , Alla I. Yemets 1 , Nataliya S. Finiuk 2 , Rostyslav R. Stoika 2 and Yaroslav B. Blume 1 * 1 DepartmentofGenomicsandMolecularBiotechnology,InstituteofFoodBiotechnologyandGenomics,NationalAcademyofSciencesofUkraine, Osipovskogo St. 2a, Kyiv 04123, Ukraine 2 DepartmentofCellProliferationandApoptosis,InstituteofCellBiology,NationalAcademyofScienceofUkraine,DrahomanovSt.14/16,Lviv79005, Ukraine Abstract Different transformation systems and vectors have been improved to increase the effectiveness of transformation and achieve stable expression of target genes. Because classical direct and indirect transformation processes commonly suffer from instability of a gene in the environment, gene deletion, transgene silencing, and poor gene transfer eficiency. Nowadays, gene transformation technologies are based on the use of new carriers (nanoparticles, carbon nanotube, whiskers, and polymers) characterized by better eficiency and reproducibility for the direct DNA delivery into the cells. In this review, we have focused on the novel DMAEM-based direct DNA delivery system and its possible applications for cell transformation. Keywords: cationic polymers (CPs); non-viral gene delivery system; plant cell transfection; poly(dimethylamino- ethylmethacrylate) (pDMAEM) Introduction Controlled delivery of plasmid DNA is one of the limiting factors in the development of the plant biotechnology industry. Methods of pDNA delivery can be classiied into two main groups: the indirect method, using Agrobacterium; and the direct methods used in plant species where Agrobacterium-mediated transformation is not possible. Direct methods can be physical (electroporation, particle bombardment, micro-injection, etc.) or chemical (polyeth- ylene glycol, polyvinyl alcohol, DMSO, etc.). Although, Agrobacterium-mediated transformation became a com- monly used technique, it has several drawbacks, which include: limitation in carrying restricted size base-pairs (<500 kb), chance of transgene silencing, and poor gene transfer eficiency (Rafsanjani et al., 2012). To improve transformation eficiency, a new approach for the gene transfer focused mainly on polymers has been proposed (Slita et al., 2007). Polymers are long-chained structures, created by polymerization of many monomers. Polymers with only a single type of repeat unit are homopolymers, whereas polymers containing a mixture of repeat units are copolymers (Cevher et al., 2012). When these systems are combined with plasmid DNA, they are called polyplexes. Polymer selection differs because to structure, achieving the desired chemical, mechanical and biological functions is required for the effective gene delivery. Usually, as polymeric vector used cationic polymers (CPs), generally bear protonable amines. Some CPs, such as poly-L-lysine (pLL), is linear polymers, while others, like polyethylenimine (pEI) and dendrimers, are highly branched chains. Some CPs have the positive charges on their backbone (as in pEI), whereas they are on side groups in, for example, pLL. Polycations offer a range of advantages over other DNA transporting agents because of ease of production, non- immunogenicity, low risk of side effects, and simplicity of DNA-polymer complex formation. Their combination with DNA forms compact interpolyelectrolyte complexes (IPEC) in a solution by electrostatic bonds between negatively charged DNA phosphate groups and positively charged groups of the polycations (Slita et al., 2007). Inclusion of DNA in an IPEC signiicantly changes its properties: increased DNA resistance to the action of nucleases and enhanced adsorption to the cell membrane due to masking of the negative DNA charges (De Smedt et al., 2000). Interaction between ions/solvents and DNA-macromolecule 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 Journal MSP No. Dispatch: September 20, 2014 CE: Dinesh CBIN 10381 No. of Pages: 3 PE: Marion Laws & Nick Toma à Corresponding author: e-mail: cellbio@cellbio.freenet.viaduk.net 1 Cell Biol Int 9999 (2014) 1–3 © 2014 International Federation for Cell Biology