Modifying Self-Assembled Peptide Cages To Control Internalization into Mammalian Cells

Area of Science:

• Biotechnology
• Materials Science
• Cell Biology

Background:

• Nanoparticles offer potential for delivering biological cargoes into eukaryotic cells.
• Polypeptides are versatile building blocks for constructing nanoscale delivery systems.
• Self-Assembled Geodesic Encapsulations (SAGEs) are peptide cages previously assembled from de novo designed coiled-coil modules.

Purpose of the Study:

• To investigate the impact of charged peptide extensions on the endocytosis of SAGE particles by cultured human cells.
• To demonstrate tunable control over nanoparticle-cell interactions through rational peptide design.

Main Methods:

• De novo design and assembly of coiled-coil peptide modules into SAGE nanoparticles.
• Functionalization of SAGE modules with charged peptide extensions (polylysine and polyglutamate).
• Assessment of coiled-coil stability and cellular uptake (endocytosis) of modified SAGE particles by human cells.

Main Results:

• Peptide extensions influenced coiled-coil stability, with N-terminal polylysine and C-terminal polyglutamate tags being destabilizing.
• Cationic SAGE particles exhibited significantly faster and greater internalization by cells compared to unmodified SAGEs.
• Anionic SAGE particles demonstrated markedly inhibited cellular uptake.

Conclusions:

• The modular SAGE system allows for rational peptide design to precisely tune nanoparticle bioactivity.
• Engineered SAGE nanoparticles with tailored surface charges can serve as effective, tunable cell-delivery vehicles.
• This approach facilitates the development of advanced nanomedicines for targeted cellular delivery.