Certain short polycations, such as TAT and polyarginine, rapidly pass through the plasma membranes of mammalian cells by an unknown mechanism called transduction as well as by endocytosis and macropinocytosis. These cell-penetrating peptides (CPPs) promise to be medically useful when fused to biologically active peptides. I offer a simple model in which one or more CPPs and the phosphatidylseri...

Protein therapy exhibits several advantages over small molecule drugs and is increasingly being developed for the treatment of disorders ranging from single enzyme deficiencies to cancer. Cell-penetrating peptides (CPPs), a group of small peptides capable of promoting transport of molecular cargo across the plasma membrane, have become important tools in promoting the cellular uptake of exogeno...

Viral diseases affect hundreds of millions of people worldwide, and the few available drugs to treat these diseases often come with limitations. The key obstacle to the development of new antiviral agents is their delivery into infected cells in vivo. Cell-penetrating peptides (CPPs) are short peptides that can cross the cellular lipid bilayer with the remarkable capability to shuttle conjugate...

PURPOSE Cell-penetrating peptides (CPPs) are used for delivering drugs and other macromolecular cargo into living cells. In this paper, we investigated the relationship between the structural/physicochemical properties of four new synthetic peptides containing arginine-tryptophan in terms of their cell membrane penetration efficiency. METHODS The peptides were prepared using solid phase synth...

Efficient delivery of heterologous molecules for treatment of cells is a great challenge in modern medicine and pharmacology. Cell-penetrating peptides (CPPs) may improve efficient delivery of a wide range of macromolecular cargos, including plasmid DNA, small interfering RNA, drugs, nanoparticulate pharmaceutical carriers, and anticancer drugs. In this paper, we present the history of CPPs' di...

The transient gene delivery systems are generally mediated by viral infection, particle bombardment, electroporation, and microinjection for transferring exogenous DNAs into host cells. Recently, the peptide-mediated DNA delivery system became a novel tool for gene transfer, and these peptides, such as cell-penetrating peptides (CPPs), contained the ability of permeating plasma membranes and ca...

High molecular weight biomolecules are becoming increasingly important in the development of new therapeutics. However, the hydrophilic nature and size of such molecules creates a major limitation for their application – poor penetration through biological membranes. Over a decade ago, a new class of peptides, cell-penetrating peptides (CPPs), with membrane translocating ability, was discovered...

Cell-penetrating peptides (CPPs) are peptides able to promote uptake of various cargos, including proteins and plasmids. Advances in recent years imply the uptake to be endocytic, where the current hurdle for efficient intracellular delivery is material being retained in the endosomes. In this study we wanted to compare the ability of various established CPPs to deliver siRNA and induce gene si...

Nanoparticles, such as semiconductor quantum dots (QDs), have been found increasing use in biomedical diagnosis and therapeutics because of their unique properties, including quantum confinement, surface plasmon resonance, and superparamagnetism. Cell-penetrating peptides (CPPs) represent an efficient mechanism to overcome plasma membrane barriers and deliver biologically active molecules into ...

Protein transduction domains comprised of basic amino acid-rich peptides, can efficiently deliver covalently fused macromolecules into cells. Quantum dots (QDs) are luminescent semiconductor nanocrystals that are finding increasing application in biological imaging. Previous studies showed that protein transduction domains mediate the internalization of covalently attached QDs. In this study, w...