Nonviral gene transfer into fetal mouse livers (a comparison between the cationic polymer PEI and naked DNA)

Abstract

We investigated the efficacy and safety of the cationic polymer polyethylenimine (PEI) as a potential tool for intrauterine gene delivery into livers of fetal mice in the last trimester of pregnancy (E17.5). Using luciferase as a reporter gene, transferrin-conjugated and ligand-free PEI/ DNA complexes (containing 3 mg DNA) with varying PEInitrogen/DNA-phosphate (N/P) ratios and different PEI forms, branched (800, 25 kDa) and linear (22 kDa), were compared with naked DNA. Transgene expression was measured 48 h after administration of PEI/DNA complexes or naked DNA. Highest luciferase activity (9.8 Â 10 3 relative light units (RLU)/mg of tissue protein) was observed with ligand-free PEI22/DNA mixtures at N/P 6.0. In addition, this formulation was associated with very low toxicity as compared to the other PEI/DNA-injected groups. Using b-galactosidase as a reporter gene, transfection of single, but also small, clusters of cells was demonstrated throughout the liver. Injection of 3 mg naked DNA resulted in an 11-fold lower transgene expression value (0.9 Â 10 3 RLU/mg of tissue protein) as compared to PEI22/DNA complexes. However, the administration of higher concentrated naked DNA (9 mg) into fetal livers yielded expression levels of 3.2 Â 10 4 RLU/mg of tissue protein, a more than three-fold increase compared to PEI22/DNA complexes. Furthermore, the gene transfer efficacy of concentrated naked DNA was approximately 40 times higher in fetuses than in adults (0.8 Â 10 3 RLU/mg of tissue protein), indicating that fetal tissue is especially amenable to the uptake and expression of naked DNA.

Regional gene therapy for full‐thickness articular cartilage lesions using naked DNA with a collagen matrix

“…Gharwan and colleagues reported that the gene transfer efficacy of naked DNA was approximately 40 times higher in fetuses than in adults, indicating that fetal tissue is especially amenable to the uptake and expression of naked DNA. 55 This result supports both our hypothesis that stem cells subjacent to a full-thickness lesion are likely amenable to taking up naked DNA and expressing our protein to augment repair, as well as the concept of using naked DNA combined with a cationic carrier such as collagen for efficient transient gene delivery.…”

Characterization of the transgene expression generated by branched and linear polyethylenimine-plasmid DNA nanoparticles in vitro and after intraperitoneal injection in vivo

“…The toxicity that arises with PEI administration is associated with charged PEI-pDNA nanoparticles interacting with blood components such as erythrocytes, causing aggregation in the lung capillaries and subsequent lung embolism. [34,58,59] Injecting PEI-pDNA nanoparticles intravenously or intratracheally results in gene expression that is stronger in the lung than liver, heart, spleen or kidneys. [30,34] Because the peritoneal cavity acts as barrier to PEI-pDNA nanoparticles entering the lung or bypassing the blood-brain barrier, PEI-pDNA nanoparticles injected via this route are expected to demonstrate significantly reduced toxicity.…”

Gene delivery to differentiated neurotypic cells with RGD and HIV Tat peptide functionalized polymeric nanoparticles

“…Polyethylenimine (PEI) is currently the most popular polymer used to deliver genes into various cell types [10][11][12][13], including neurons [10,11]. PEI is able to condense genes into small nanoparticles [14] and protect the DNA from degradation by nucleases [15].…”