This record provides bibliographic details and links to the original research. An editorial study breakdown is not available.
What the researchers found
The dimerized (doubled) form of the CAP18-derived peptide, called (sC18)2, was easily attached to extracellular vesicle (EV) membranes when linked to a fat-loving molecule. Once attached, the peptide triggered macropinocytosis, a process where cells engulf large amounts of surrounding fluid and particles.
This dramatically increased how many EVs got inside target cells. The process depended on glycosaminoglycans (sugar chains on cell surfaces). The team showed this could deliver a functional toxin protein (saporin) that was loaded into the EVs by electroporation.
The saporin-loaded, peptide-modified EVs killed target cells, proving the cargo reached the inside of the cell and was biologically active.
Why it matters
Extracellular vesicles are promising drug delivery vehicles because cells naturally take them up. But uptake is often too low for therapeutic use. This peptide modification solves that problem by forcing cells to gulp in more EVs, opening the door to EV-based delivery of proteins, toxins, or other drugs.
The numbers in context
(sC18)2 peptide modification; glycosaminoglycan-dependent macropinocytosis; saporin toxin delivery confirmed
How the study worked
Researchers modified the (sC18)2 peptide with a hydrophobic (fat-loving) anchor so it would stick to EV membranes. They tested cellular uptake in multiple cell lines (CHO, HeLa, MCF-7). They loaded saporin toxin into EVs by electroporation and measured cell killing to confirm intracellular delivery. They also tested which uptake pathway was responsible using pathway-blocking experiments.
Who was studied
Cell lines (CHO, HeLa, MCF-7; in vitro)
What this study cannot tell us
All experiments were done in cell lines in the lab, not in animals or humans. The study did not test whether the peptide-modified EVs cause immune reactions in a living body. Long-term stability of the peptide coating was not assessed. Only one toxin payload was tested.
Read the original research
Macropinocytosis-Inducible Extracellular Vesicles Modified with Antimicrobial Protein CAP18-Derived Cell-Penetrating Peptides for Efficient Intracellular Delivery.
Molecular pharmaceutics, 18(9), 3290-3301
Citation
Noguchi, Kosuke; Obuki, Momoko; Sumi, Haruka; Klußmann, Merlin; Morimoto, Kenta; Nakai, Shinya; Hashimoto, Takuya; Fujiwara, Daisuke; Fujii, Ikuo; Yuba, Eiji; Takatani-Nakase, Tomoka; Neundorf, Ines; Nakase, Ikuhiko. (2021). Macropinocytosis-Inducible Extracellular Vesicles Modified with Antimicrobial Protein CAP18-Derived Cell-Penetrating Peptides for Efficient Intracellular Delivery.. Molecular pharmaceutics, 18(9), 3290-3301. https://doi.org/10.1021/acs.molpharmaceut.1c00244