Comparative evaluation of synthetic polyarginine peptides to deliver nucleic acids In vitro

Among different cell penetrating peptides (CPPs), the arginine rich CPPs (AR-CPPs) have been shown to efficiently translocate in cells. In the present study, peptides comprising seven, nine and twelve residues length were synthesized in linear and dimeric format. These peptides were evaluated for their ability to deliver nucleic acid cargo in MDBK cells. Initially, the translocation ability of these peptides was determined by observing the intracellular fluorescence of FITC labeled peptides on translocation of MDBK cells. Thereafter, nucleic acid cargos i.e., FITC labeled oligonucleotides and plasmid construct consisting of GFP gene was delivered in cells using these peptides. The dimeric polyarginine peptides showed good cell penetrating efficiency and translocated in cells. At the same time, fluorophore labeled oligonucleotides were efficiently carried inside cells, when delivered using these peptides. Among all the dimeric polyarginine peptides tested, the dimeric seven-mer peptide successfully delivered reporter plasmid construct in cells.