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

Abstract

Polyethylenimine (PEI) is a cationic polymer that has shown significant potential for delivering genes in vitro and in vivo. Mixing cationic PEI with negatively charged plasmid DNA (pDNA) results in the spontaneous electrostatic formation of stable nanoparticle complexes. The structure of PEI can be branched or linear. In this study, we show that branched PEI has a stronger electrostatic interaction with pDNA than linear PEI, which accounts for greater compaction, higher zeta potentials and smaller nanoparticle sizes at equivalent pDNA concentrations. For both linear and branched PEI, increasing the concentration of pDNA mixed in the same volume and at the same nitrogen to phosphate (N:P) ratio results in larger average particle sizes. Increasing the N:P ratio increases luciferase activity generated by branched PEI-pDNA nanoparticles and linear PEI-pDNA nanoparticles in HEK293, COS7 and HeLa cell lines. Increasing the N:P ratio at which branched PEI-pDNA nanoparticles are prepared also increases luciferase expression in HepG2 cells but does not increase luciferase expression generated by linear PEI-pDNA nanoparticles. In all of the cell lines, branched PEI-pDNA nanoparticles prepared at N:P ratios of 10 and above generated significantly higher luciferase activity than linear PEI-pDNA nanoparticles. Luciferase activity was highest in the HEK293 cells and luciferase expression in each of the cell lines followed the order of HEK293<COS7<HepG2<HeLa. Intraperitoneal (IP) injection of PEI-pDNA nanoparticles is attractive because it is simple, reproducible and often leads to a depot effect of nanoparticle complexes residing in the peritoneum. The IP route of administration avoids PEI-pDNA nanoparticle accumulation in the lung and the nanoparticles do not pass through the blood-brain barrier. In this study, using bioluminescent imaging (BLI), we show that changing the PEI structure and dose of the PEI-pDNA nanoparticles has a significant impact on the strength and duration of transgene expression after IP injection in vivo but increasing the N:P ratio does not. Increasing the dose and N:P ratio for all the PEI-pDNA nanoparticle formulations injected IP did not reduce mice survival and all mice remained in good health as determined by the Body Condition Scoring (BCS) technique.

Polyethylenimine600-&beta;-cyclodextrin: a promising nanopolymer for nonviral gene delivery of primary mesenchymal stem cells

“…**P , 0.05. Abbreviations: PEI 600 -β-CyD, polyethylenimine 600 -β-cyclodextrin; MSCs, mesenchymal stem cells; ALP, alkaline phosphatase; BMP, bone morphogenetic protein; SATB2, Special AT-rich sequence-binding protein 2. high efficiency exhibited by PEI25kDa in terms of gene delivery both in vitro and in vivo, 27 the high cytotoxicity and serious tissue damage caused by this high-MW PEI still need to be examined. 28,29 Recent studies have focused on enhancing the efficiency of low-MW PEI without altering its cytotoxicity.…”

Polymer nanoparticles for cross-presentation of exogenous antigens and enhanced cytotoxic T-lymphocyte immune response

“…19 In this study, cationic-charged PEI was introduced in order to overcome this limitation and to deliver antigens effectively into DCs via the proton-sponge effect. [20][21][22][23][24][25] We chose ovalbumin (OVA) as a model antigen, which has been well characterized for estimates of cross-presentation efficiency. In our study, we explored the effects of PEI-coated PLGA NPs containing OVA on the viability and phenotype of DCs, and analyzed the capacity and mechanism of PEI-coated PLGA NPs for antigen delivery and cross-presentation in DCs.…”

Degradable copolymer based on amphiphilic N-octyl-N-quatenary chitosan and low-molecular weight polyethylenimine for gene delivery

“…At the same time, the complexes with surface positive charges were easily taken up by the lung due to electrostatic interaction. [28][29][30][31] Therefore, in our future work, we intend to modify a tumor-targeted group to improve cell selection.…”