Phosphonate lipid tubules II.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biochemistry

Background:

• Tubule-forming lipids are crucial in self-assembly and biomaterials.
• The archetypal molecule 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC(8,9)PC) forms stable tubules under mild conditions.
• Modifying the lipid's backbone can alter self-assembly properties and resulting structures.

Purpose of the Study:

• To synthesize and characterize a novel chiral phosphonate analogue of DC(8,9)PC.
• To investigate the self-assembly behavior and structural properties of the new phosphonate lipid.
• To compare the tubule formation and morphology of the phosphonate analogue with the parent phosphocholine molecule.

Main Methods:

• Chemical synthesis of the chiral phosphonate lipid analogue.
• Synchrotron small-angle X-ray scattering (SAXS) for structural analysis.
• Atomic force microscopy (AFM) and optical microscopy for morphological characterization.

Main Results:

• The phosphonate analogue successfully formed tubules under mild conditions, similar to DC(8,9)PC.
• The new tubules exhibited significantly larger diameters (1.94x), were shorter, and had thinner walls compared to DC(8,9)PC tubules.
• A notable portion of the phosphonate precipitate formed stable, enantiomerically pure open helices, with an almost even distribution of left- and right-handed forms.

Conclusions:

• Replacing the C-O-P linkage with a C-P linkage in tubule-forming lipids yields distinct structural characteristics.
• The chiral phosphonate analogue offers a new platform for creating self-assembled structures with tunable morphologies, including helices.
• This study expands the library of self-assembling molecules and provides insights into structure-property relationships in lipid-based nanomaterials.