Charge Type, Charge Spacing, and Hydrophobicity of Arginine-Rich Cell-Penetrating Peptides Dictate Gene Transfection

Noncovalent complexation of plasmid DNA (pDNA) with cell-penetrating peptides (CPPs) forms relatively large complexes with poor gene expression. Yet, condensing these CPP-pDNA complexes via addition of calcium chloride produces small and stable nanoparticles with high levels of gene expression. This simple formulation offered high transfection efficiency and negligible cytotoxicity in HEK-293 (a virus-immortalized kidney cell) and A549 (a human...