Structural investigation of sulfobetaines and phospholipid monolayers at the air-water interface

DOI: 10.1039/D2CP02695C
Data DOI: 10.15125/BATH-00917

Authors: Naomi Elstone (University of Bath) , Thomas Arnold (University of Bath; European Spallation Source ERIC; Diamond Light Source; ISIS Neutron Source Facility) , Maximilian W. A. Skoda (ISIS Neutron Source Facility) , Simon E. Lewis (University of Bath) , Peixun Li (ISIS Neutron and Muon Source) , Gavin Hazell (University of Bath) , Karen J. Edler (University of Bath)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Chemistry Chemical Physics

State: Published (Approved)
Published: September 2022
Diamond Proposal Number(s): 11542

Abstract: Mixtures of sulfobetaine based lipids with phosphocholine phospholipids are of interest in order to study the interactions between zwitterionic surfactants and the phospholipids present in cell membranes. In this study we have investigated the structure of mixed monolayers of sulfobetaines and phosphocholine phospholipids. The sulfobetaine used has a single 18-carbon tail, and is referred to as SB3-18, and the phospholipid used is DMPC. Surface pressure-area isotherms of the samples were used to determine whether any phase transitions were present during the compression of the monolayers. Neutron and X-Ray reflectometry were then used to investigate the structure of these monolayers perpendicular to the interface. We found that the average headgroup and tail layer thickness was reasonably consistent across all mixtures with a variation of less than 3 Å reported in the total thickness of the monolayers at each surface pressure. However, by selective deuteration of the two components of the monolayers, it was found that the two components have different tail layer thicknesses. For the mixture with equal compositions of DMPC and SB3-18 or with a higher composition of DMPC the tail tilts were found to be constant, resulting in a greater tail layer thickness for SB3-18 due to its longer tail. For the mixture higher in SB3-18 this was not the case, the tail tilt angle for the two components was found to be different and DMPC was found to have a greater tail layer thickness than SB3-18 as a result.

Subject Areas: Chemistry, Physics, Medicine


Instruments: I07-Surface & interface diffraction

Other Facilities: INTER at ISIS

Added On: 12/09/2022 09:09

Documents:
d2cp02695c.pdf

Discipline Tags:

Surfaces Drug Delivery Physics Physical Chemistry Health & Wellbeing Chemistry interfaces and thin films Life Sciences & Biotech

Technical Tags:

Diffraction X-ray Reflectivity (XRR)