Cooperative Cellular Uptake and Activity of Octaarginine Antisense Peptide Nucleic Acid (PNA) Conjugates

Abstract

Cellular uptake and antisense activity of d-octaarginine conjugated peptide nucleic acids (PNAs) is shown to exhibit pronounced cooperativity in serum-containing medium, in particular by being enhanced by analogous mis-match PNA–cell-penetrating peptide (PNA–CPP) conjugates without inherent antisense activity. This cooperativity does not show cell or PNA sequence dependency, suggesting that it is a common effect in cationic CPP conjugated PNA delivery. Interestingly, our results also indicate that Deca-r8-PNA and r8-PNA could assist each other and even other non-CPP PNAs as an uptake enhancer agent. However, the peptide itself (without being attached to the PNA) failed to enhance uptake and antisense activity. These results are compatible with an endosomal uptake mechanism in which the endocytosis event is induced by multiple CPP–PNA binding to the cell surface requiring a certain CPP density, possibly in terms of nanoparticle number and/or size, to be triggered. In particular the finding that the number of endosomal events is dependent on the total CPP–PNA concentration supports such a model. It is not possible from the present results to conclude whether endosomal escape is also cooperatively induced by CPP–PNA.

Precise Engineering of Cisplatin Prodrug Into Supramolecular Nanoparticles: Enhanced on in Vitro Antiproliferative Activity and Treatment and Care of in Vivo Renal Injury 

“…Lysotracker CIS-PT-NPs with Dil (Molecular Probe, USA) stained the cell lysosome (red color), then DAPI stained the nuclei. Images were examined by confocal laser scanning microscopy (CLSM) utilizing the image analyzer software manufacturer's protocol [35][36][37].…”

Evolution of peptide nucleic acid with modifications of its backbone and application in biotechnology

“…For enhanced cellular delivery, PNA has been conjugated with cell penetrating peptide (CPP), cationic peptides, and basic amino acid stretches such as lysine and arginine ( Figure 5). The delivery of aggregated PNA into the cells is an endocytic process though cationic peptides, and CPP-conjugated PNA is also reported to be partially translocated through endocytosis (El-Andaloussi et al, 2006;Ghavami et al, 2019;Turner et al, 2007). The aggregated PNA complex gets trapped in the endosome in most cases decreasing the availability of the PNA for antigene, antisense, and anti-miR activity ( Figure 5).…”

“…Still, CPP is a large peptide molecule and its conjugation with PNA and other nucleic acids is a cumbersome process. Small cationic peptides were reported to deliver the PNA into the cells efficiently (Ghavami et al, 2019). The cationic peptides designed for this purpose either have large numbers of positively charged lysine and arginine amino acids in its sequence (El-Sayed et al, 2009) or having alternate patterns of charged and hydrophobic amino acids to form an amphiphilic oligo peptide structure (Crombez et al, 2009).…”

Multifunctional Delivery Systems for Peptide Nucleic Acids

“…This correlated with the formation of PNA nanoparticles that acted as carrier for all the PNA components. These nanoparticles were found to be formed in the presence of serum proteins, which were effectively detected in the nanoparticle pellet [ 216 ].…”