Gene delivery to neuroblastoma cells by poly (l-lysine)-grafted low molecular weight polyethylenimine copolymers

Abstract

Polyethylenimine (PEI) and poly (l-lysine) (PLL) are among the most investigated non-viral gene carriers. However, both polymers contain deficiencies that restrict their applications. In the present study, we synthesized PLL-alkyl-PEI conjugates via 6-carbon alkyl linker and investigated their possible advantages in gene delivery. Four PLL copolymers were synthesized with different molecular weights and ratios of PEI. The physiochemical properties of synthesized conjugates such as size, zeta potential, DNA condensation ability, buffering capacity and cytotoxicity were investigated. Renilla luciferase assay was employed to evaluate the gene transfection efficiency of pDNA-polymer to Neuro2A cell line. DNA condensation and particle size measurements showed that new PLL-PEI conjugates could form polyplexes in nano-scale size in the range of 99-122 nm and were able to condense DNA at low concentration. While cytotoxicity reduced in some groups, the transfection efficiency increased about 2.8 and 4 fold as compared to the unmodified PEI 1.8 kDa and 10 kDa, respectively. The results of the present study showed that the chemical modifications of PEI with PLL could significantly improve transfection efficiency and PLP10-10% shows the most promise as a new gene carrier.

Evaluation and comparison of cytotoxicity, genotoxicity, and apoptotic effects of poly-l-lysine/plasmid DNA micro- and nanoparticles

“…[8][9][10][11][12] PLL is a natural cationic polymer with positively charged side chain, due to the presence of amino acid lysine as the repeat unit, this polymer is biodegradable and this property considers it as a remarkable candidate for in vivo applications such as drug delivery and cell tracking. [13][14][15] PLL polymer can act as a vehicle for different cargoes such as drugs, peptides, and genes 16,17 and also as a promising coating agent for improving biocompatibility of different nanoparticles for cell tracking process. 18,19 Since the constitution of polyelectrolyte complexes between PLL and DNA was recognized, PLL has been extensively used as a nonviral gene carrier.…”

“…27 Therefore, using biocompatible PLL derivatives 14 or conjugation of PLL with other polymers, such as PEI opens up new venues in dealing with aforementioned issues. 8,9,15,24 Toxicity of cationic polymers attributed to many factors such as molecular weight, charge density, and structure of polymers along with other parameters, such as the time of exposure, nature of the targeted cell/tissue, and interaction with circulating agents in plasma during in vivo application. 28 In a study, a biocompatible PLL analog known as poly (a-[4-amino-butyl]-L-glycolic acid) was utilized to deliver plasmid DNA (pDNA) encoded murine interleukin 10 (IL-10) in nonobese diabetic mice.…”

Poly(hydroxy acid) Nanoparticles for the Encapsulation and Controlled Release of Doxorubicin

“…It was envisaged that due to its poly(cationic) nature, poly[(PheLA) 10.4 ‐ b ‐(LysLA) 31.4 ] may be exploited for antimicrobial applications and gene delivery . However, its polycationic nature also dictates that this PHA could pose cytotoxicity problems to healthy cells if it were to be used for drug delivery in vivo .…”

Nanoparticles as Drug Delivery Systems of RNAi in Cancer Therapy

“…Therefore, many researchers are committed to modifying the structure of low molecular weight PEI (LMW-PEI) to improve its safety and transfection efficiency and decrease the unnecessary cytotoxicity in vivo. For instance, the surface of PEI can be modified by covalent bonds with PEG [ 103 ], polysaccharides [ 104 ], and hydrophobic groups [ 105 ]. The PEI-polymers based on polysaccharides can improve the half-life of blood circulation and avoid the clearance of reticuloendothelial cells [ 106 ].…”