Cholesterol improves the transfection efficiency of polyallylamine as a non-viral gene delivery vector

Abstract

Cationic polymers such as polyallylamine (PAA) having primary amino groups are poor transfection agents and possess a high cytotoxicity index when used without any chemical modification. In this study, PAA was modified with cholesterol in order to improve transfection efficiency and to reduce cytotoxicity. PAA polymers with molecular weights of 15 and 65 kDa were selected and grafted with cholesterol at percentages of 5, 10, 15, 30, and 50. After purification, the efficacy of the synthetic vectors was evaluated in terms of DNA condensation using the ethidium bromide test, buffering capacity, particle size, zeta potential, transfection efficiency, and cytotoxicity assay in Neuro2A cell lines. According to the ethidium bromide test, these vectors can condense DNA at moderate and high carrier to plasmid (C/P) ratios. The buffering capacity of the prepared vector in both molecular weights was less than unmodified PAA. Particle size measurements demonstrated that modified PAAs were able to form nanoparticles ranging in size from 125 to 530 nm. The vectors based on PAA 15 kDa demonstrated a better transfection efficiency than the vectors made of PAA 65 kDa. Cytotoxicity studies showed that toxicity of all vectors was less than PAA. Some cholesterol modified polymers composed of PAA (15 kDa) were suitable vectors for gene delivery with low cytotoxicity.

Modified PAMAM vehicles for effective TRAIL gene delivery to colon adenocarcinoma: in vitro and in vivo evaluation

“…According to other reports, cholesterol-derived cationic lipids and polymers may enhance gene transfection efficacy including cholesterol-PEI conjugates, and Gemini-cholesterol lipids [39,40]. Oskuee et al [41] showed that binding of cholesterol to specific serum ligands can raise the rate of polyplex entrance into the cell by ligand-mediated endocytosis.…”

Self-Assembled Oleic Acid-Modified Polyallylamines for Improved siRNA Transfection Efficiency and Lower Cytotoxicity

“…PAH is a linear polycation with primary amines previously studied as a potential nucleic acid carrier for siRNA delivery. , PAH has been also modified with cholesterol, , methylglycolate, and several acrylates in order to improve its delivery efficiency for siRNA and pDNA. In this work, a 17.5 kDa PAH was covalently modified with OA via amide bonds using carbodiimide chemistry.…”

Nonviral vector system for cancer immunogene therapy

“…Polymer nanoparticles include poly(cyanoacrylate) (PCA), poly(D,L-lactide-coglycolide) (PLGA), poly(glutamic acid) (PGA), polyamidoamine (PAA), poly(ε-caprolactone) (PCL), polyethyleneimine (PEI), polyaminoester (PAE), poly(ethylene oxide) and poly(L-lysine) (PLL), poly dimethylaminoethylmethacrylate (PDMAEMA) and poly(D,L-lactide) (PLA). [119][120][121][122] Polymer nanoparticles usually have a high density of amine groups that can be protonated at physiological pH when mixed with negatively charged nucleic acids to form stable complexes through electrostatic interactions and entropy changes. 123,124 Studies have shown that nanoparticles containing immunomodulators can efficiently deliver mRNA and siRNA.…”