Functionalized Coiled-Coil Peptide Nanocrystals for Cellular Protein Delivery

Peptide-based crystalline nanomaterials with a well-defined growth mechanism remain an unexplored avenue for efficient cellular protein delivery. Herein, we report the formation of Ni(II)-promoted coiled-coil peptide nanocrystals that demonstrate periodic banding and open hexagonal packing. Mechanistic experiments provide insights into the thermodynamic and kinetic interactions involved in crystal growth. Further, metal–ligand interactions facilitate protein inclusion within the crystals, and surface modification with a His-tagged cell-penetrating peptide was harnessed to achieve enhanced protein delivery to cells. As such, an understanding of coiled-coil interactions in nanocrystals may enable the development of modular morphologies via controlled crystal growth with an expansion of biomedical applications.