Peptide-Based Complex Coacervates Stabilized by Cation-π Interactions for Cell Engineering

Area of Science:

• Biomaterials Science
• Molecular Biology
• Nanotechnology

Background:

• Complex coacervation involves liquid-liquid phase separation of oppositely charged macromolecules.
• Peptide-based coacervates are emerging as effective intracellular delivery vehicles for large biomolecules.
• Understanding coacervate assembly/disassembly is crucial for optimizing cargo delivery and release kinetics.

Purpose of the Study:

• To design and characterize histidine-rich peptides for tunable complex coacervate formation.
• To investigate the role of specific amino acid residues and intermolecular interactions in coacervate stability.
• To evaluate the potential of these peptide coacervates for intracellular delivery of various macromolecules.

Main Methods:

• Systematic incorporation of cationic, anionic, and aromatic residues into peptide sequences.
• Modulation of intermolecular interactions, including cation-π interactions, to control coacervation.
• Grafting of disulfide-based self-immolative side chains to enhance stability and control release.
• In vitro and in cellulo testing for delivery of proteins, mRNA, and CRISPR/Cas9 systems.

Main Results:

• Cation-π interactions between arginine and aromatic residues significantly stabilize peptide coacervates.
• Coacervate disassembly and cargo release are triggered in protein-rich intracellular environments.
• Grafted coacervates demonstrate enhanced stability and efficient delivery of diverse cargo, including mRNA and CRISPR/Cas9.
• Successful delivery was achieved in challenging cell types, such as macrophages.

Conclusions:

• Peptide-based coacervates offer a versatile platform for intracellular delivery.
• Cation-π interactions are key to designing stable and responsive coacervates.
• This approach expands the potential of peptide coacervates in biomedicine and biotechnology, particularly for gene editing applications.