Evaluation of genotoxicity and cytotoxicity induced by different molecular weights of polyethylenimine/DNA nanoparticles

Abstract

Nonviral gene delivery systems are considered to be a safe alternative to the viral system used in gene therapy. Although polyethylenimine (PEI) is among the most promising gene-carrier candidates for efficient nonviral gene delivery, safety concerns regarding its toxicity remain challenging. The aim of this study was to evaluate the less considered aspects of toxicity including genotoxicity effects of branched PEI with different molecular weights (1800 Da, 25 kDa, 750 kDa). Neuro2A mammalian cells were cultured in DMEM with 10% FBS and exposed to PEI/DNA complexes at different polymer/DNA ratios (known as the C/P ratio). To evaluate metabolic activities and genotoxicity, the treated cells were subjected to MTT and comet assays, respectively. Intracellular reactive oxygen species were also determined by using the fluorescent dye dichlorofluorescin diacetate. Concentration with relation to toxicity, genotoxicity, and ROS production was observed in Neuro2A cells treated with PEI/DNA nanoparticles. The difference among toxicities induced by different molecular weights of PEI at higher C/P ratios was significant, whereas no significant toxicity effect was induced by PEI at C/P ratios of 1 and lower. We found concentration-dependent genotoxicity and a direct correlation between nanoparticle concentrations and DNA damage, which cannot be ignored and should be considered for the design of new generations of PEI derivatives with enhanced delivery properties and reduced toxicity.

Tetraiodothyroacetic acid-conjugated polyethylenimine for integrin receptor mediated delivery of the plasmid encoding IL-12 gene

“…According to the previous findings, the PEI cytotoxic effects occur during two different phases including an early necrotic stage which begins around 30 min after exposure resulting from the perturbation of the cell membranes. This stage might be followed by an apoptotic phase which occurs 24 h later [64,67]. The results of our study showed that the unmodified PEI was able to induce remarkable apoptosis on the A375 cells whereas the conjugation of the targeting ligand of tetrac substantially reduced its apoptotic effects.…”

Efficient Non-Viral Gene Modification of Mesenchymal Stromal Cells from Umbilical Cord Wharton’s Jelly with Polyethylenimine

“…Recent studies show the cytotoxic effects of PEI are caused by a series of different mechanisms, mainly disruption of the different membranes of the cell [ 57 ], including the outer cell membrane as well as internal membranes (i.e., endosome, mitochondria, endoplasmic reticulum (ER), Golgi apparatus and nuclear membrane) [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. Other mechanisms include affected gene expression [ 58 ]. As a result, cytotoxicity of PEI remains a challenging issue, further complicated by the lack of clarity related to what PEI’s ultimate fate is, whether it is exocytosed or degraded (at least partially).…”

Comparative study of cytotoxicity and genotoxicity of commercial Jeffamines® and polyethylenimine in CHO‐K1 cells

“…BPEI and LPEI did not cause significant DNA damage compared with negative control, in the range of concentrations used in this work. In previous studies, BPEI 25 kDa resulted to be non‐genotoxic on mouse Neuro 2A cells when evaluated using comet assay . Another study showed DNA damage can be induced by BPEI 25 kDa in human Jukart T cells, at concentrations of 1, 3, and 5 µg/mL (0.04, 0.12, and 0.2 µM).…”