Water behaves fundamentally differently in biological environments than in bulk. Inside cells, for instance, water is confined in crowded settings where it is strongly coupled to surrounding interfaces. In their latest study, researchers from the group of Prof. Yang Yao used lipidic mesophases as a model membrane system to relate interfacial curvature and water connectivity to the structure and dynamics of confined water.

Lipidic mesophases: tunable model systems for confined water studies

In biological systems, water rarely exists as a homogeneous bulk liquid. Instead, water is often confined within crowded environments and continuously interacts with nearby interfaces, which drive its structure and dynamics. In their recent work, Prof. Yang Yao and her team established a direct link between the confining geometry of lipidic mesophases (LMPs) and the behavior of water, thereby extending the influence of the environment beyond mere confinement size. LMPs are self-assembled lipid nanostructures formed by mixing lipids with water. By tuning hydration and temperature, the researchers exerted control over the topology in these systems, which allowed them to progress from planar to curved and finally disconnected geometries, as illustrated in the above figure. 

How geometry reshapes confined water behavior

In the lamellar phase L_α, tightly packed lipid chains form planar interfaces that promote strong lipid-water hydrogen bonding, resulting in two distinct water populations: slow, interfacial water located near the lipid interface, and faster, more bulk-like core water residing at the center of the aqueous domains. 

Upon transition to the cubic phase Iad, lipid chains become more flexible while the interface bends towards the water, reducing the specific interfacial area per lipid and disrupting hydrogen-bonding, which weakens the interaction between the lipids and water. Meanwhile, the formation of 3D-connected water channels enhances long-range charge transport. 

In the reverse micellar phase L₂, lipid bilayers break up and aqueous connectivity is lost. Despite high lipid mobility, charge transport slows down due to isolated water domains, while strong interfacial curvature causes interfacial and core water dynamics to converge, reflecting a highly disordered hydrogen-bond network.

From confining geometry to advanced materials design

Together, these results establish a clear geometric principle: interfacial curvature and aqueous connectivity jointly control the packing of lipids, hydrogen bonding, the dynamics of confined water, and charge transport in lipidic materials. With this framework, the team around Prof. Yang Yao provides a conceptual toolbox for designing lipid-based systems in which confined water mediates key processes such as molecular transport and enzyme activity. 

Original publication [1]
Sara Catalini, Matteo Rutsch, Andrea Lapini, Barbara Rossi, Mariangela Di Donato, Brenda Bracco, Marco Paolantoni, Yang Yao
Geometry Controls Confined Water Dynamics in Lipidic Mesophases
Angew. Chem. Int. Ed. 2026, e22757, https://doi.org/10.1002/anie.202522757