Synthesis and characterization of 2‐diethyl‐aminoethyl–dextran–methyl methacrylate graft copolymer for nonviral gene delivery vector

Abstract

ABSTRACT:A stable and soapless latex of 2-diethyl-aminoethyl (DEAE)-dextran-methyl methacrylate (MMA) graft copolymer (DDMC) was developed for nonviral gene delivery vectors (complex between polycation and nucleic acid). DDMC was newly prepared using MMA and DEAE-dextran. Following a transfection protocol, transfection of HEK 293 cells by DDC1, DDC2, and DDC3 samples was carried out using plasmid DNA. With the transfection efficiency determined using the X-Gal staining method, a higher value of 5 times or more was confirmed for DDMC samples DDC1 and DDC2 (but not for DDC3) than for the starting DEAEdextran hydrochloride. The absorption spectrum shift at around 3400 cm Ϫ1 of the complexes between DDMC and DNA may support the formation of more compact structures by a Coulomb force between the phosphoric acid of DNA and the DEAE group of DEAE-dextran, concluding in DNA condensation. The specifically designed molecular structure of DDMC to ensure easy entry of DNA into cells needs not only a positive charge and a hydrophilic-hydrophobic microseparated domain but also more compact structures for transfection steps.

Mechanism of Introduction of Exogenous Genes into Cultured Cells Using DEAE-Dextran-MMA Graft Copolymer as Non-Viral Gene Carrier

“…When comparing transfection efficiency for DEAE-dextran (graft ratio 0%) and DDMC in transfection experiments carried out using HEK293 cells, remarkable results, to have an amphiphilic domain in order to form a polymer micelle, were obtained with DDMC (graft ratio 130%) [5,6,7,8,9]. …”

“…Although these compounds have problems with cytotoxicity and low transformation rates, they have a history of use as nonviral vectors, and desirable DEAE-dextrans (2-diethylaminoethyl-dextran) are currently being closely investigated because they can be sterilized [3,4]. Copolymers formed by graft polymerization of methyl methacrylate (MMA) with DEAE-dextran have hydrophilic and hydrophobic regions and are known to be desirable non-viral vectors due to their high transformation efficiency [5,6,7]. Thus, complexes of DNA and DEAE-dextran-MMA graft copolymer (DDMC) produced by modification of DEAE-dextran has been reported to have superior transformation efficiency of 50× or more relative to DEAE-dextran in terms of transformation efficiency in various types of cell [8].…”

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

“…Characteristics of the 2-diethylaminoethyl-dextran methyl methacrylate graft copolymer: DDMC is a copolymer that is formed through grafting MMA onto DEAE–dextran as the backbone polymer by using a tetravalent ceric salt [14]. It generates a polymer micelle that forms a microphase-separated structure with a hydrophilic domain for the DEAE–dextran part and a hydrophobic domain for the graft polymer PMMA.…”

“…That is, from Fig. 1, the absorbance variation of DEAE–dextran/DNA is large, so that there is a large amount of toluidine blue because the decomposition of DNA by DNase is promoted in the presence of DEAE–dextran/DNA from the earliest stage [15]. Conversely, for DDMC/DNA, the DNA decomposition hardly progressed, but the absorbance variation was very small.…”

Supramolecular Facilities to Melanoma Cells B16F10 with Nanoparticles of a DEAE-Dextran-MMA Copolymer-Paclitaxel Complex

“…The resulting DDMC consists of 'hairy' nanoparticles with an amphiphilic domain (DEAE-dextran) and a hydrophobic domain (MMA polymer, PMMA) that form a polymer micelle [11]. It has been reported that DDMC is superior to other transfection with safety transfection efficacy by autoclaved as a non-viral carrier for gene introduction [12][13][14][15][16][17][18].…”