Modification of the Linker Amino Acid in the Cell-Penetrating Peptide NickFect55 Leads to Enhanced pDNA Transfection for In Vivo Applications

Abstract

Despite numerous efforts over the last three decades, nucleic acid-based therapeutics still lack delivery platforms in the clinical stage. Cell-penetrating peptides (CPPs) may offer solutions as potential delivery vectors. We have previously shown that designing a “kinked” structure in the peptide backbone resulted in a CPP with efficient in vitro transfection properties. Further optimization of the charge distribution in the C-terminal part of the peptide led to potent in vivo activity with the resultant CPP NickFect55 (NF55). Currently, the impact of the linker amino acid was further investigated in the CPP NF55, with the aim to discover potential transfection reagents for in vivo application. Taking into account the expression of the delivered reporter in the lung tissue of mice, and the cell transfection in the human lung adenocarcinoma cell line, the new peptides NF55-Dap and NF55-Dab* have a high potential for delivering nucleic acid-based therapeutics to treat lung associated diseases, such as adenocarcinoma.

The menace of severe adverse events and deaths associated with viral gene therapy and its potential solution

“…Another experiment showed that NF55/pDNA complexes with both modified and unmodified linkers could transfect cells in vivo, mostly targeting lung cells. 422 Similar studies of CPP/pDNA complex transfection were conducted for several other CPPs, namely PepFect14, CPP foldamers, DOT1L, Scp01-b, and HR9, but most were conducted in vitro. [423][424][425][426][427] Many studies illustrate another approach, in which CPPs are placed on NP surface to increase cell membrane penetration.…”

“…CPPs can be used for gene delivery both on their own and as a component of other delivery system. 420 In a recent study, Härk et al 422 used NickFect55 CPP with modified amino acid linker in complex with pDNA to transfect CHO cells, reaching over 60% transfection efficiency. Another experiment showed that NF55/pDNA complexes with both modified and unmodified linkers could transfect cells in vivo, mostly targeting lung cells.…”

Enhancing Cellular Uptake of Native Proteins through Bio-Orthogonal Conjugation with Chemically Synthesized Cell-Penetrating Peptides

“…Once the intein undergoes self-excision, the protein and CPP are joined together through a peptide bond. Structures were generated using Mol* [44] software and Marvin [45].…”