Self-Assembly of Surfactant-like Peptides Steve S. Santoso, Sylvain Vauthey & Shuguang Zhang Center for Biomedical Engineering Massachusetts Institute of Technology

Nanostructures Structures ranging from 1 to 100 nm Sub-micrometer science and engineering that combine multiple disciplines: Chemistry Biology Physics Material science Engineering How to build / design nanostructures? Want the atomic selectivity of synthetic chemistry yet the expandability of engineering Molecular self-assembly may be useful

Self-assembly processes common in biological systems: Cell membrane Multi-component cellular machinery: ribosome Protein folding Self-assembly involves non-covalent bonding van der Waals hydrogen bonds dipolar forces dynamic process

Surfactant-like peptides [Ac]-VVVVVVD Six hydrophobic valines (tail) One polar aspartic acid (head) 2 nm

Preliminary experiments and results Some condition screening Use: dynamic light scattering (DLS), TEM Found larger structures for some conditions:

Cryo-TEM: 300 nm

Nanotubes are not the structure with energetic global minimum:

Nanovesicle RF Controlled delivery of small chemicals Use nanovesicle to study replication of biological materials in an enclosed environment

150 nm 550 nm

Summary Peptide surfactants are promising substrates for advanced material and its application. Cost-effective Certain structures will form under certain environmental and chemical conditions Tunable Biological origin may be advantageous for medical application A good system to study self-assembly.