3-Helix micelles stabilized by polymer springs.
Despite increasing demands to employ amphiphilic micelles as nanocarriers and nanoreactors, it remains a significant challenge to simultaneously reduce the particle size and enhance the particle stability. Complementary to covalent chemical bonding and attractive intermolecular interactions, entropic repulsion can be incorporated by rational design in the headgroup of an amphiphile to generate small micelles with enhanced stability. A new family of amphiphilic peptide-polymer conjugates is presented where the hydrophilic headgroup is composed of a 3-helix coiled coil with poly(ethylene glycol) attached to the exterior of the helix bundle. When micelles form, the PEG chains are confined in close proximity and are compressed to act as a spring to generate lateral pressure. The formation of 3-helix bundles determines the location and the directionalities of the force vector of each PEG elastic spring so as to slow down amphiphile desorption. Since each component of the amphiphile can be readily tailored, these micelles provide numerous opportunities to meet current demands for organic nanocarriers with tunable stability in life science and energy science. Furthermore, present studies open new avenues to use energy arising from entropic polymer chain deformation to self-assemble energetically stable, single nanoscopic objects, much like repulsion that stabilizes bulk assemblies of colloidal particles.
Department of Materials Science and Engineering, University of California-Berkeley, Berkeley, California, USA.
He
H
Dong
Jessica Y
JY
Shu
Nikhil
N
Dube
Yufei
Y
Ma
Matthew V
MV
Tirrell
Kenneth H
KH
Downing
Ting
T
Xu
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D019793:Fluorescein / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D049329:Nanostructures; D010455:Peptides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
D008823:Micelles; D010455:Peptides; D011092:Polyethylene Glycols; D019793:Fluorescein