Influence of Polymer Architecture and Molecular Weight of Poly(2-(dimethylamino)ethyl methacrylate) Polycations on Transfection Efficiency and Cell Viability in Gene Delivery

Abstract

Nonviral gene delivery with the help of polycations has raised considerable interest in the scientific community over the past decades. Herein, we present a systematic study on the influence of the molecular weight and architecture of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) on the transfection efficiency and the cytotoxicity in CHO-K1 cells. A library of well-defined homopolymers with a linear and star-shaped topology (3- and 5-arm stars) was synthesized via atom transfer radical polymerization (ATRP). The molecular weights of the polycations ranged from 16 to 158 kDa. We found that the cytotoxicity at a given molecular weight decreased with increasing number of arms. For a successful transfection a minimum molecular weight was necessary, since the polymers with a number-average molecular weight, M(n), below 20 kDa showed negligible transfection efficiency at any of the tested polyelectrolyte complex compositions. From the combined analysis of cytotoxicity and transfection data, we propose that polymers with a branched architecture and an intermediate molecular weight are the most promising candidates for efficient gene delivery, since they combine low cytotoxicity with acceptable transfection results.

Cargo–carrier interactions significantly contribute to micellar conformation and biodistribution

“…[3][4][5][6][7] Often carriers with cationic net charge interact strongly with and are capable of penetrating the cellular membrane, leading to high delivery efficiencies but this is often accompanied by impaired cell viability and clearance by the reticuloendothelial system. 8,9 An interesting class of nanocarriers is block copolymer micelles with diameters below 50 nm as these are reported to deeply penetrate tumor tissue in spite of elevated interstitial pressure. 10 In addition, PEGylation generally facilitates long circulation times while, ideally, a surface-tag might induce specific interaction of the particle with the targeted cells or tissues.…”

Effect of peptide content on the regulation of transgene expression by protein kinase Cα-responsive linear polyethylenimine-peptide conjugates

“…Polyplexes with H(S)-7.9 at an N/P ratio of 10 also showed almost no cytotoxicity, while those at an N/P ratio of 20 had some cytotoxicity, but not significant. Previous studies have reported that poylcations with higher M w , such as PEI [40] and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) [41], show more cytotoxicity than those with lower M w . In our study, H(S)-7.9 with the largest M w at an N/P ratio of 20 showed a slight cytotoxicity toward cells.…”

Influence of Polyplex Formation on the Performance of Star-Shaped Polycationic Transfection Agents for Mammalian Cells

“…For instance, non-linear polymers appear to be more efficient and less cytotoxic than linear polymers of the same size [6,13,14]. Recently, our group has published first data showing that star-shaped nano-structures with many arms extending from a central core may result in non-viral polycationic transfection agents with the ability to transfect cells, which up to then had been considered unsuitable targets for non-viral gene delivery [15].…”