Library of Cationic Polymers Composed of Polyamines and Arginine as Gene Transfection Agents

Abstract

Combinatorially synthesized materials, especially cationic polymers (CPs), with gene transfection function hold great promise in nanotechnology. However, the main limitations of the existing CPs [such as polyethylenimine (PEI), poly-L-arginine, or polyamidoaminebased dendrimers] as gene transfection agents are high cytotoxicity in the physiological environment. We have developed novel CPs composed of polyaminesendogeneous tetraamine spermine (Spm) and synthetically made triamine N-(2-aminoethyl)-1,3-propanediamine (Apd) for incorporating sec-amino groups and imparting PEI-like structure to the CP backbones. Naturally occurring building blocks such as amino acid arginine (R) was also used for incorporating guanidine-groups into the CPs. The cytotoxicity of resulting CPspolyureas (PUs) and polyamides such as polysuccinamides and R-attached polymalamides was evaluated using murine and human fibroblasts and carcinoma cell lines. The cell compatibility screening revealed that the CPs made of Apd are less cytotoxic compared to Spm-based analogues. From the novel polymer library, total of six polymers were further studied for oligonucleotide (pDNA) complexation and transfection abilities. Highly water-soluble CPs formed nano-sized polyplexes with pDNA at rather low CP/pDNA weight ratios and showed less cytotoxicity and higher transfection ability compared to widely used PEI as well as commercially available transfection agents. Furthermore, new CPs showed selective transfection activity toward certain cell lines (4T1, HeLa, NIH3T3, and CCD 27SK), which is important for their potential applications in gene therapy.

Oligoarginine Peptides, a New Family of Nicotinic Acetylcholine Receptor Inhibitors

“…After finding the cholinergic effects with the oligoarginine peptides, we hypothesized that other CPs also might show antagonistic properties toward nAChRs and we investigated this with three compounds (see Fig. 1B) synthesized for intracellular gene delivery (Memanishvili et al, 2014;Zavradashvili et al, 2014Zavradashvili et al, , 2019. Binding tests showed competition of 2ApdC and 8R3 with 125 I-aBgt for binding to human a7 nAChR on GH4C1 cells (Fig.…”

“…Thus, activity against nAChRs was tested for three compounds (see Fig. 6; Table 4) synthesized for intracellular gene delivery (Memanishvili et al, 2014;Zavradashvili et al, 2014Zavradashvili et al, , 2019. We detected competition of 2ApdC and 8R3 but not of tES-ED-R(Me) with 125 I-aBgt for binding to a7 nAChR on GH4C1 cells.…”

“…The cationic polyamide 2ApdC (R-free) composed of succinic acid (2) and N-(2-aminoethyl)-1,3-propanediamine (Apd) was synthesized as hydrochloride salt (C) by solution polycondensation of trihydrochloric acid salt of triamine Apd (ApdC3) with activated diester di-pnitrophenyl succinate (NSu) (Zavradashvili et al, 2019). Molecular mass characteristics of the polymer were as follows: molecular mass 5 8.34 kDa, Mn 5 2.80 kDa, and Ð 5 2.2697 (gel permeation chromatography in hexafluoroisoparpanol).…”

“…1 and all methods, receptors, and models used are listed in Table 1. With regard to oligoarginines, we should add that cationic polymers (CPs) are an effective, biodegradable instrument for intracellular delivery of nucleic acids and other negatively charged molecules. CPs have notable potential for use in gene therapy and drug delivery (Zavradashvili et al, 2019). All CPs have a cationic nature and some contain arginine residues.…”

“…All CPs have a cationic nature and some contain arginine residues. This is why we performed a binding assay and functional tests on several recently synthesized CPs (Memanishvili et al, 2014;Zavradashvili et al, 2019) and demonstrated their effects on nAChRs. Thus, our results show that oligoarginines are a new group of nAChR inhibitors that may be useful in nAChR research, and this property should be taken into account when applying oligoarginines and related compounds for drug delivery.…”