Over the last decade, researchers have studied cell-penetrating peptides for delivering cargoes across cell membranes. These peptides carry low molecular weight drugs, imaging agents, peptides, oligonucleotides, proteins, and carriers like liposomes and polymeric nanoparticles. Their non-toxic…
In the past ten years, scientists have examined cell-penetrating peptides, known as CPPs, for their capacity to pass the cell membrane barrier. This allows intracellular or transcellular transport of various cargoes. Examples include low molecular weight drugs, imaging agents, peptides, oligonucleotides, proteins, and colloidal carriers such as liposomes and polymeric nanoparticles.
These peptides move across biological plasma membranes without disruption and show no clear toxicity. Such properties make them valuable for improving drug bioavailability. Researchers seek structural details to predict uptake mechanisms of these transport peptides.
Proposed factors include positive charges on side chains of Arg or Lys residues. Other elements are Trp or Phe residues in specific positions, amphiphilicity of the peptide, and the polypeptide chain length. Despite many studies, the uptake process of CPPs lacks full clarification.
To advance CPP applications in research and therapy, rational design of new transport peptides proves essential. Comparisons between CPPs with positive charges and their neutralized versions help. Studies also assess sequences of cationic amino acid residues and clustering of net positive charges.
A key challenge in developing therapeutic agents involves poor bioavailability of hydrophilic compounds. Drugs targeting intracellular sites must cross the lipid bilayer membrane to work. CPPs address this by enabling transport across mammalian cell plasma membranes.
These peptides often carry a positive net charge or amphipathic nature. They differ in other traits but enter cells without relying on energy or receptors, unlike receptor-mediated carriers. Sometimes called protein transduction domains or PTDs, CPPs offer distinct advantages.
Polypeptides and oligonucleotides hold limited value in biomedical research and pharmaceuticals due to low membrane permeability and quick degradation. Intracellular access to biological targets would expand if large-sized hydrophobic molecules could reach inside cells. This avoids restrictions from crossing lipid bilayers.
CPPs cross the plasma membrane of living cells and enable cargo transport inside. Cargoes include conjugated peptides, proteins, oligonucleotides, and nanoparticles. The exact process remains unclear, but this ability creates new opportunities in biomedical research and therapy.
Debate continues on the protein transduction mechanism. Still, CPPs quickly enter cells and deliver therapeutics across situations and systems. Their efficient, non-invasive cargo delivery supports uses in drug delivery, gene transfer, and DNA vaccination.
CPPs hold promise for broad clinical applications. They influence fields from drug delivery to gene transfer and DNA vaccination. While unanswered questions and usage limits persist, this technology offers significant clinical potential.
Reference:
Ling Ren. COMPARISON OF CELLULAR UPTAKE OF ARGININE-RICH CELL-PENETRATING PEPTIDES
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