Calcium Condensation of DNA Complexed with Cell-Penetrating Peptides Offers Efficient, Noncytotoxic Gene Delivery

Abstract

Drug delivery strategies using cell penetrating peptides (CPPs) have been widely explored to improve the intracellular delivery of a large number of cargo molecules. Electrostatic complexation of pDNA using CPPs has been less explored due to the relatively large complexes formed and the low levels of gene expression achieved when using these low molecular weight polycations as DNA condensing agents. Here, condensing nascent CPP polyplexes using CaCl2 produced small and stable nanoparticles leading to gene expression levels higher than observed for control PEI gene vectors. This simple formulation approach showed negligible cytotoxicity in A549 lung epithelial cells and maintained particle size and transfection efficiency even in the presence of serum.

Arginine-rich cell-penetrating peptides deliver gene into living human cells

“…3-5). These data were in agreement with previous results that condensation of nascent CPP/DNA polyplexes by calcium chloride produces small (100-140 nm) and stable nanoparticles, leading to the enhancement of gene expression levels (Baoum and Berkland, 2011). This formulation approach showed negligible cytotoxicity and maintained particle size and transfection efficiency even in the presence of serum (Baoum and Berkland, 2011).…”

“…A549 cells were then supplemented with 100 μl of 10% serumcontaining medium and incubated at 37°C for 48 h. After 2 days, cells were stained with Hoechst 33342 and observed using a BD Pathway 435 system (BD Biosciences). The influence of calcium for gene delivery was reported (Baoum and Berkland, 2011). Cells were treated with either the pEGFP-N1 plasmid DNA only or CPP/DNA complexes in the absence or presence of 113 mM of calcium chloride according to the functional gene assay.…”

A gene delivery system for insect cells mediated by arginine-rich cell-penetrating peptides

“…To our knowledge, neither further application nor scientific article has appeared after the publication from Ogay et al (2006). Additionally, PEI was considered as one of efficient currently-available transfection reagents, but this molecule is not biodegradable and relatively cytotoxic (Fischer et al, 1999;Forrest et al, 2003;Baoum and Berkland, 2011;our unpublished data). Transfection efficiencies of 6.67% (Fig.…”

Polyarginine Molecular Weight Determines Transfection Efficiency of Calcium Condensed Complexes

“…Polyethylenimine (PEI), polylysine and similar polycations can mediate high levels of gene expression, but high molecular weight polycations are often required to effectively condense the DNA to small particles. 1–10 The needed increase in molecular weight; however, often increases cytotoxicity. 2, 11–13 Cytotoxicity of polycations may be minimized by different approaches such as conjugation with hydrophilic or degradable polymers (e.g.…”

“…11, 14–16 A simple alterative is to identify ways to form small polyplexes using less cytotoxic polycations such as cell penetrating peptides (CPPs). 1, 17–19 …”