Poly(ethylene imine)‐g‐chitosan using EX‐810 as a spacer for nonviral gene delivery vectors

Abstract

Polyelectrolyte complexes have been widely studied as gene carriers in recent years. In this study, poly (ethylene imine) was grafted onto chitosan (PEI-g-CHI) as a nonviral gene carrier in order to improve the water solubility as well as the inherent transfection efficiency of chitosan. We present a novel method to conjugate the amine or hydroxyl groups of chitosan (CHI) and the amine groups of PEI through opening the epoxide rings of ethylene glycol diglycidyl ether (EX-810), which also brings the merits as mentioned in PEGylation chemistry. The degree of substitution of PEI onto CHI was characterized by NMR. The preliminarily cellular mechanisms, from the cellular entry to the endosomal release, were investigated by the correlations among the physicochemical properties of the DNA-polymer complexes, the buffering capacity of the modified polymer, the cytotoxicity, and the efficiency of the transgene expression. The cytotoxicity assayed by MTT shows that cell viability of PEI-g-CHI is higher than CHI especially noticeable at high concentrations using human kidney 293T cells. The efficiency of transgene expression and the amount of intracellular plasmid were monitored using green fluorescent protein (GFP) and visualized by fluorescence microscopy. The transfection efficiency of PEI-g-CHI/DNA polyplex is significantly better than CHI/DNA polyplex when using the weight ratios higher than 2.5.

Polymeric Nanoparticles of Chitosan Derivatives as DNA and siRNA Carriers

“…The transfection efficiency of NSCgraft-PEI/DNA complexes was found to be higher than that of PEI/DNA complexes, and the transfection efficiency of NSC-graft-PEI/DNA complexes was not affected by the presence of serum. Lou et al synthesized PEI-graft-chitosan using ethylene glycol diglycidyl ether as a spacer in order to increase the water solubility and transfection efficiency of chitosan [71]. The transfection efficiency of 16 Y.K.…”

“…The transfection efficiency was not affected by serum [70] Ethylene glycol diglycidyl ether was used as a spacer to improve the water solubility of chitosan. The transfection efficiency of the PEI-graft-chitosan was increased as compared with chitosan [71] 1,1 0 -carbonyldiimidazole was used as a linking agent between chitosan and PEI. Long-term transfection efficiency of the chitosan-graft-PEI was higher than for PEI 25K in vitro [72] Akt1 siRNA Chitosan-graft-PEI efficiently delivered Akt1 siRNA and thereby silenced onco-protein Akt1 in A549 cells [73] MAA RhoA siRNA MAA/TMC/siRNA complexes exhibited higher inhibition of RhoA mRNA expression than did TMC/siRNA complexes [74] Polymeric Nanoparticles of Chitosan Derivatives as DNA and siRNA Carriersexpression in 293T and HepG2 cells due to escape of the complexes from the endosomes.…”

Low Molecular Weight Chitosan (LMWC)-based Polyplexes for pDNA Delivery: From Bench to Bedside

“…Electron microscopy has also been employed to measure particle size, but smaller results in particle size are obtained compared to DLS. Some authors have attributed this increment in particle size by DLS characterization due to the fact that, particles are fully hydrated when characterized by DLS [37] or that they are not spherical [38].…”

Gold Nanoparticles: Synthesis, Characterization, and Bioconjugation

“…Amine containing molecules are well known to be widely used as reducing agents for nanoaprticles synthesis and stabilization. 35 When polyelectrolytes such as chitosan, polyallylamine and polyethylenimine are present during the synthesis of nanoparticles, positively charged nanoparticles can be otained, 36 the presence of this positive charges on the surface of the nanoparticles maybe of benifits for electrostatic complexation for biomolecules such as the phosphate esters backbones of the nucleic acid, [37][38][39] while the more general process for the bioconjugation of nanoprticles is known to occur through formation of a biologically stable amide linkage between the NH2 groups of the biomolecules and carboxylic acid at the surface of the nanoparticles or vice versa. [40][41][42] The attachment of biomolecules such as peptides, proteins and other targeted ligands containing specific molecules that recognize receptors on various cell lines on the surface of nanoparticles plays a key role not only for their interactions with biological tissues, but also in their biological functions and cellular uptake, that can facilitate their use in drug delivery, diagnosis and therapeutics.…”