Fluctuation X-ray diffraction reveals three-dimensional nanostructure and disorder in self-assembled lipid phases

• Published in: Communications materials Vol. 1; no. 1; pp. 1 - 8
• Main Authors: Martin, Andrew V., Kozlov, Alexander, Berntsen, Peter, Roque, Francisco Gian, Flueckiger, Leonie, Saha, Saumitra, Greaves, Tamar L., Conn, Charlotte E., Hawley, Adrian M., Ryan, Timothy M., Abbey, Brian, Darmanin, Connie
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.07.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/541/966; 639/925/930/2735; Chemistry and Materials Science; Diffraction patterns; Hexagonal phase; Lipids; Materials Science; Membranes; Metal-organic frameworks; Nanomaterials; Organic materials; Phase separation; Phospholipids; Self-assembly; Small angle X ray scattering; Structural analysis; Synchrotrons
• ISSN: 2662-4443; 2662-4443
• DOI: 10.1038/s43246-020-0044-z

Emergent nanoscale order in materials such as self-assembled lipid phases, colloidal materials and metal-organic frameworks is often characterized by small-angle X-ray scattering (SAXS). Frequently, residual disorder in these materials prevents high-resolution 3D structural characterization. Here we demonstrate that angular intensity variations in SAXS patterns can provide previously inaccessible information about local 3D structure via a rich, real-space distribution of three- and four-body statistics. We present the many-body characterisation of a monoolein-based hexagonal phase doped with a phospholipid, revealing non-uniform curvature in the lipid channels, likely due to phase separation of the lipids in the membrane. Our many-body technique has general applicability to nanomaterials with order in the range 10 nm −1  μm currently targeted by synchrotron SAXS and has the potential to impact diverse research areas within chemistry, biology and materials science. Emergent nanoscale order in organic materials is typically characterized by small-angle X-ray scattering. Here, angular fluctuations in the diffraction patterns are used to probe the 3D structure of self-assembled lipid membranes, revealing previously inaccessible details on the phase geometry.