  Polypeptide-based diblock copolymers forming either well-defined
self-assembled micelles or vesicles after direct dissolution in water or in
dichloromethane, have been studied combining light and neutron scattering with
electron microscopy experiments. The size of these structures could be
reversibly manipulated as a function of environmental changes such as pH and
ionic strength in water. Compared to other pH-responsive seld-assembled systems
based on "classical" polyelectrolytes, these polypeptide-based nanostructures
present the ability to give a response in highly salted media as the chain
conformational ordering can be controlled. This makes these micelles and
vesicles suitable for biological applications: they provide significant
advantages in the control of the structure and function of supramolecular
self-assemblies.
