Cell-Penetrating Peptides: Emerging Tools for mRNA Delivery

Messenger RNAs (mRNAs) were previously shown to have great potential for preventive vaccination against infectious diseases and therapeutic applications in the treatment of cancers and genetic diseases. Delivery systems for mRNAs, including lipid- and polymer-based carriers, are being developed for improving mRNA bioavailability. Among these systems, cell-penetrating peptides (CPPs) of 4–40 amino acids have emerged as powerful tools for mRNA delivery, which were originally developed to deliver membrane-impermeable drugs, peptides, proteins, and nucleic acids to cells and tissues. Various functionalities can be integrated into CPPs by tuning the composition and sequence of natural and non-natural amino acids for mRNA delivery. With the employment of CPPs, improved endosomal escape efficiencies, selective targeting of dendritic cells (DCs), modulation of endosomal pathways for efficient antigen presentation by DCs, and effective mRNA delivery to the lungs by dry powder inhalation have been reported; additionally, they have been found to prolong protein expression by intracellular stabilization of mRNA. This review highlights the distinctive features of CPP-based mRNA delivery systems.

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Oligoalanine helical callipers for cell penetration

Chemical Communications ◽

10.1039/c8cc02304b ◽

2018 ◽

Vol 54 (50) ◽

pp. 6919-6922 ◽

Cited By ~ 6

Author(s):

Marta Pazo ◽

Marisa Juanes ◽

Irene Lostalé-Seijo ◽

Javier Montenegro

Keyword(s):

Amino Acids ◽

Rational Design ◽

Chemical Space ◽

Cell Penetrating Peptides ◽

Short Peptides ◽

Cell Penetration ◽

Basic Amino Acids ◽

Cell Penetrating ◽

Natural Amino Acids

Even for short peptides that are enriched in basic amino acids, the large chemical space that can be spanned by combinations of natural amino acids hinders the rational design of cell penetrating peptides.

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Novel approaches in development of cell penetrating peptides

Journal of Applied Pharmaceutical Research ◽

10.18231/joapr.2021.9.1.08.24 ◽

2021 ◽

Vol 9 (1) ◽

pp. 1-7

Author(s):

Vatsal R. Shah ◽

Yamini D. Shah ◽

Mansi N. Athalye

Keyword(s):

Drug Delivery ◽

Side Effects ◽

Drug Delivery Systems ◽

Cell Penetrating Peptides ◽

Delivery Systems ◽

Endosomal Escape ◽

Effective Drug ◽

Cell Penetrating ◽

Potential Benefits ◽

Novel Approaches

Therapeutic cargos which are impermeable to the cell can be delivered by cell penetrating peptides (CPPs). CPP-cargo complexes accumulate by endocytosis inside the cells but they fail to reach the cytosolic space properly as they are often trapped in the endocytic organelles. Here the CPP mediated endosomal escape and some strategies used to increase endosomal escape of CPP-cargo conjugates are discussed with evidence. Potential benefits can be obtained by peptides such as reduction in side effects, biocompatibility, easier synthesis and can be obtained at lower administered doses. The particular peptide known as cell penetrating peptides are able to translocate themselves across membrane with the carrier drugs with different mechanisms. This is of prime importance in drug delivery systems as they have capability to cross physiological membranes. This review describes various mechanisms for effective drug delivery and associated challenges

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Molecular dynamics study of the internalization of cell-penetrating peptides containing unnatural amino acids across membranes

Nanoscale Advances ◽

10.1039/d1na00674f ◽

2021 ◽

Author(s):

Joan Gimenez-Dejoz ◽

Keiji Numata

Keyword(s):

Molecular Dynamics ◽

Amino Acids ◽

Unnatural Amino Acids ◽

Biological Membranes ◽

Cell Penetrating Peptides ◽

Delivery Systems ◽

Cell Penetrating ◽

Target Molecules

Peptide-based delivery systems that deliver target molecules into cells have been gaining traction. These systems need cell-penetrating peptides (CPPs), which have the remarkable ability to penetrate into biological membranes and...

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Breaking in and busting out: cell-penetrating peptides and the endosomal escape problem

BioMolecular Concepts ◽

10.1515/bmc-2017-0023 ◽

2017 ◽

Vol 8 (3-4) ◽

pp. 131-141 ◽

Cited By ~ 34

Author(s):

Julia C. LeCher ◽

Scott J. Nowak ◽

Jonathan L. McMurry

Keyword(s):

Cell Penetrating Peptides ◽

Endosomal Escape ◽

Great Promise ◽

Delivery Methods ◽

Oligomeric Proteins ◽

Cell Penetrating ◽

History Of ◽

A Cell ◽

Escape Problem ◽

Primary Focus

AbstractCell-penetrating peptides (CPPs) have long held great promise for the manipulation of living cells for therapeutic and research purposes. They allow a wide array of biomolecules from large, oligomeric proteins to nucleic acids and small molecules to rapidly and efficiently traverse cytoplasmic membranes. With few exceptions, if a molecule can be associated with a CPP, it can be delivered into a cell. However, a growing realization in the field is that CPP-cargo fusions largely remain trapped in endosomes and are eventually targeted for degradation or recycling rather than released into the cytoplasm or trafficked to a desired subcellular destination. This ‘endosomal escape problem’ has confounded efforts to develop CPP-based delivery methods for drugs, enzymes, plasmids, etc. This review provides a brief history of CPP research and discusses current issues in the field with a primary focus on the endosomal escape problem, for which several promising potential solutions have been developed. Are we on the verge of developing technologies to deliver therapeutics such as siRNA, CRISPR/Cas complexes and others that are currently failing because of an inability to get into cells, or are we just chasing after another promising but unworkable technology? We make the case for optimism.

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Leaky Fusion Between Intraluminal Vesicles Of Late Endosomes That Have An Unusual Lipid Composition As A Mechanism Of Endosomal Escape By Cell-penetrating Peptides

Biophysical Journal ◽

10.1016/j.bpj.2008.12.1815 ◽

2009 ◽

Vol 96 (3) ◽

pp. 359a

Author(s):

Sung-Tae Yang

Keyword(s):

Lipid Composition ◽

Cell Penetrating Peptides ◽

Endosomal Escape ◽

Late Endosomes ◽

Cell Penetrating

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Tumour lineage-homing cell-penetrating peptides as anticancer molecular delivery systems

Nature Communications ◽

10.1038/ncomms1952 ◽

2012 ◽

Vol 3 (1) ◽

Cited By ~ 89

Author(s):

Eisaku Kondo ◽

Ken Saito ◽

Yuichi Tashiro ◽

Kaeko Kamide ◽

Shusei Uno ◽

...

Keyword(s):

Cell Penetrating Peptides ◽

Delivery Systems ◽

Molecular Delivery ◽

Cell Penetrating

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Decoding the Entry of Two Novel Cell-Penetrating Peptides in HeLa Cells: Lipid Raft-Mediated Endocytosis and Endosomal Escape†

Biochemistry ◽

10.1021/bi048330+ ◽

2005 ◽

Vol 44 (1) ◽

pp. 72-81 ◽

Cited By ~ 83

Author(s):

Christina Foerg ◽

Urs Ziegler ◽

Jimena Fernandez-Carneado ◽

Ernest Giralt ◽

Robert Rennert ◽

...

Keyword(s):

Lipid Raft ◽

Hela Cells ◽

Cell Penetrating Peptides ◽

Endosomal Escape ◽

Cell Penetrating

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Development of helix-stabilized cell-penetrating peptides containing cationic α,α-disubstituted amino acids as helical promoters

Bioorganic & Medicinal Chemistry ◽

10.1016/j.bmc.2017.01.044 ◽

2017 ◽

Vol 25 (6) ◽

pp. 1846-1851 ◽

Cited By ~ 13

Author(s):

Hiroko Yamashita ◽

Takashi Misawa ◽

Makoto Oba ◽

Masakazu Tanaka ◽

Mikihiko Naito ◽

...

Keyword(s):

Amino Acids ◽

Cell Penetrating Peptides ◽

Cell Penetrating ◽

Disubstituted Amino Acids

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Stereochemistry as a determining factor for the effect of a cell-penetrating peptide on cellular viability and epithelial integrity

Biochemical Journal ◽

10.1042/bcj20180155 ◽

2018 ◽

Vol 475 (10) ◽

pp. 1773-1788 ◽

Cited By ~ 4

Author(s):

Ditlev Birch ◽

Malene V. Christensen ◽

Dan Staerk ◽

Henrik Franzyk ◽

Hanne Mørck Nielsen

Keyword(s):

Amino Acids ◽

Cell Viability ◽

Mammalian Cells ◽

Membrane Integrity ◽

Cell Penetrating Peptides ◽

Proliferating Cells ◽

Epithelial Integrity ◽

Cell Penetrating ◽

Culture Models ◽

Well Differentiated

Cell-penetrating peptides (CPPs) comprise efficient peptide-based delivery vectors. Owing to the inherent poor enzymatic stability of peptides, CPPs displaying partial or full replacement of l-amino acids with the corresponding d-amino acids might possess advantages as delivery vectors. Thus, the present study aims to elucidate the membrane- and metabolism-associated effects of l-Penetratin (l-PEN) and its corresponding all-d analog (d-PEN). These effects were investigated when exerted on hepatocellular (HepG2) or intestinal (Caco-2 and IEC-6) cell culture models. The head-to-head comparison of these enantiomeric CPPs included evaluation of their effects on cell viability and morphology, epithelial membrane integrity, and cellular ultrastructure. In all investigated cell models, a rapid decrease in cell viability, pronounced membrane perturbation and an altered ultrastructure were detected upon exposure to d-PEN. At equimolar concentrations, these observations were less pronounced or even absent for cells exposed to l-PEN. Both CPPs remained stable for at least 2 h during exposure to proliferating cells (cultured for 24 h), although d-PEN exhibited a longer half-life when compared with that of l-PEN when exposed to well-differentiated cell monolayers (cultured for 18–20 days). Thus, the stereochemistry of the CPP penetratin significantly influences its effects on cell viability and epithelial integrity when profiled against a panel of mammalian cells.

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