Express in Vitro Plasmid Transfection Achieved with 16⁺ Asymmetric Peptide Dendrimers

Asymmetric cationic amino acid-based dendrimers are highly branched chemically derived gene vectors developed to transport cargo such as plasmid DNA across the plasma membrane. We have previously demonstrated their propensity to enter cells that form caveolae, driven by positive charge density and promoted by arginine head groups. Caveolae are plasma membrane subdomains serving a number of cellular functions including endocytosis. Their formation requires membrane proteins (caveolins) and cytoplasmic proteins (cavins), so that gene disruption of either caveolin-1 or cavin-1 (also known as PTRF, i.e., polymerase I and transcript release factor) results in caveola deficiency. Here we evaluated the ability of a 16⁺ charged asymmetric arginine dendrimer to transfect plasmid DNA into cultured cells. We unveiled efficient transfection efficiencies (≥30%) 24-48 h after exposing the cells to dendrimer/pDNA complexes for only 5 min. Using wild type (WT) and caveolin-1 or PTRF gene-disrupted, i.e., caveola-deficient mouse embryo fibroblasts, we further show that caveolae promote pDNA transfection by 16⁺ charged asymmetric arginine dendrimers.