Living Bacteria-Nanoparticle Hybrids Mediated through Surface-Displayed Peptides

Area of Science:

• Biotechnology
• Materials Science
• Synthetic Biology

Background:

• Developing methods for creating stable bacteria-nanoparticle hybrids is crucial for advancing living material systems.
• Controlling nanoparticle assembly on bacterial surfaces while maintaining cell viability presents significant challenges.

Purpose of the Study:

• To investigate the preparation of living bacteria-nanoparticle hybrids mediated by surface-displayed peptides.
• To demonstrate a controllable and "biofriendly" method for assembling metallic nanoparticles onto living bacterial cells.

Main Methods:

• Engineered Escherichia coli with inducible gene circuits to control surface peptide display using enhanced circularly permuted outer membrane protein X (eCPX) scaffolds.
• Utilized metal-peptide interactions for self-assembly of citrate-stabilized gold nanoparticles onto bacteria expressing designed or known gold-binding peptides.
• Overcame electrostatic repulsion between negatively charged nanoparticles and cells to achieve conjugation.

Main Results:

• Successfully created viable bacteria/gold nanoparticle hybrids that maintained growth and division capabilities.
• Demonstrated preserved activity and stability of the bacterial hybrid assembly.
• Achieved inducible and controlled conjugation of bacterial surfaces with metal-rich nanoparticles.

Conclusions:

• The developed method enables the creation of living bacteria-nanoparticle hybrids with preserved viability.
• Surface-displayed peptides offer a versatile platform for controlled, on-demand conjugation of diverse nanoparticles to bacterial surfaces.
• This approach is a significant step toward the development of novel living material systems with tunable properties.