E3MPH16: An efficient endosomolytic peptide for intracellular protein delivery

Area of Science:

• Biotechnology
• Cell Biology
• Drug Delivery

Background:

• Engineered peptides facilitate protein delivery into cells but often cause membrane damage.
• Balancing delivery efficiency and cytotoxicity remains a challenge for current peptide delivery systems.

Purpose of the Study:

• To design and evaluate a novel endosome-disruptive cytosolic delivery peptide, E3MPH16, inspired by mastoparan X (MP).
• To improve cytosolic delivery of biomacromolecules while minimizing cell damage.

Main Methods:

• Engineered E3MPH16 by incorporating three Glu (E3) and 16 His (H16) residues onto MP.
• Assessed E3MPH16's ability to facilitate endosomal escape and cytosolic delivery of Alexa Fluor 488-labeled dextran.
• Evaluated E3MPH16-mediated delivery of Cre recombinase and anti-Ras-IgG in cell lines.
• Validated in vivo potential by topical injection of E3MPH16 with NLS-GFP into tumor xenografts.

Main Results:

• E3MPH16 demonstrated effective endosomal trapping and disruption upon endosomal acidification.
• Nearly 100% cytosolic delivery of a 10 kDa dextran was achieved with E3MPH16.
• E3MPH16 facilitated gene recombination and inhibited cell proliferation via delivered cargo.
• Successful topical in vivo delivery of NLS-GFP into tumor xenografts was achieved.

Conclusions:

• E3MPH16 is a potent endosome-disruptive peptide for enhanced cytosolic delivery.
• The peptide's design mitigates cytotoxicity while improving delivery efficiency.
• E3MPH16 shows significant potential for both in vitro and in vivo intracellular delivery applications.