The mechanical response of lipid membranes to nanoscale deformations is of fundamental importance for understanding how these interfaces behave in multiple biological processes; in particular, the nanoscale mechanics of non-lamellar membranes represents a largely unexplored research field. Among these mesophases, inverse bicontinuous cubic phase QII membranes have been found to spontaneously occur in stressed or virally infected cells and to play a role in fundamental processes, such as cell fusion and food digestion. We herein report on the fabrication of thin ( ̴150 nm) supported QII cubic phase lipid films (SQIIFs) and on their characterization via multiple techniques including Small Angle X-Ray Scattering (SAXS), Ellipsometry and Atomic Force Microscopy (AFM). Moreover, we present the first nanomechanical characterization of a cubic phase lipid membrane, through AFM-based Force Spectroscopy (AFM-FS). Our analysis reveals that the mechanical response of these architectures is strictly related to their topology and structure. The observed properties are strikingly similar to those of macroscopic 3D printed cubic structures when subjected to compression tests in material science; suggesting that this behaviour depends on the 3D organisation, rather than on the length-scale of the architecture. We also show for the first time that AFM-FS can be used for characterizing the structure of non-lamellar mesophases, obtaining lattice parameters in agreement with SAXS data. In contrast to classical rheological studies, which can only probe bulk cubic phase solutions, our AFM-FS analysis allows probing the response of cubic membranes to deformations occurring at length and force scales similar to those found in biological interactions.

Nanoscale structural and mechanical characterization of thin bicontinuous cubic phase lipid films / Ridolfi A.; Humphreys B.; Caselli L.; Montis C.; Nylander T.; Berti D.; Brucale M.; Valle F.. - In: COLLOIDS AND SURFACES. B, BIOINTERFACES. - ISSN 0927-7765. - STAMPA. - 210:(2022), pp. 112231-112231. [10.1016/j.colsurfb.2021.112231]

Nanoscale structural and mechanical characterization of thin bicontinuous cubic phase lipid films

Ridolfi A.;Caselli L.;Montis C.;Berti D.;
2022

Abstract

The mechanical response of lipid membranes to nanoscale deformations is of fundamental importance for understanding how these interfaces behave in multiple biological processes; in particular, the nanoscale mechanics of non-lamellar membranes represents a largely unexplored research field. Among these mesophases, inverse bicontinuous cubic phase QII membranes have been found to spontaneously occur in stressed or virally infected cells and to play a role in fundamental processes, such as cell fusion and food digestion. We herein report on the fabrication of thin ( ̴150 nm) supported QII cubic phase lipid films (SQIIFs) and on their characterization via multiple techniques including Small Angle X-Ray Scattering (SAXS), Ellipsometry and Atomic Force Microscopy (AFM). Moreover, we present the first nanomechanical characterization of a cubic phase lipid membrane, through AFM-based Force Spectroscopy (AFM-FS). Our analysis reveals that the mechanical response of these architectures is strictly related to their topology and structure. The observed properties are strikingly similar to those of macroscopic 3D printed cubic structures when subjected to compression tests in material science; suggesting that this behaviour depends on the 3D organisation, rather than on the length-scale of the architecture. We also show for the first time that AFM-FS can be used for characterizing the structure of non-lamellar mesophases, obtaining lattice parameters in agreement with SAXS data. In contrast to classical rheological studies, which can only probe bulk cubic phase solutions, our AFM-FS analysis allows probing the response of cubic membranes to deformations occurring at length and force scales similar to those found in biological interactions.
2022
210
112231
112231
Ridolfi A.; Humphreys B.; Caselli L.; Montis C.; Nylander T.; Berti D.; Brucale M.; Valle F.
File in questo prodotto:
File Dimensione Formato  
Ridolfi et al._AFM_CubicPhase_MainText_final.pdf

Open Access dal 20/11/2023

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: Tutti i diritti riservati
Dimensione 827.47 kB
Formato Adobe PDF
827.47 kB Adobe PDF

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1260171
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 9
social impact