Surface Plasmon Resonance Monitoring of Mono-Rhamnolipid Interaction with Phospholipid-Based Liposomes

Publication year: 2021
Authors: Belkilani M. 1,2.3, Shokouhi M. 4, Farre C. 1, Chevalier Y. 1, Minot S. 1, Bessueille F. 1, Abdelghani A. 3, Jaffrezic-Renault N. 1, Chaix C. 1

1 - CNRS, Claude Bernard Lyon 1 University, Institute of Analytical Sciences, University of Lyon, F-69100 Villeurbanne, France
2 - ENSIT, University of Tunis, 1008 Tunis, Tunisia
3 - INSAT, Research Unit of Nanobiotechnology and Valorisation of Medicinal Plants, University of Carthage, 1080 Charguia Cedex, Tunisia
4 - Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran

Published in: Langmuir, 2021, Vol. 37 (26), p. 7975–7985
doi: 10.1021/acs.langmuir.1c00846

The interactions of mono-rhamnolipids (mono-RLs) with model membranes were investigated through a biomimetic approach using phospholipid-based liposomes immobilized on a gold substrate and also by the multiparametric surface plasmon resonance (MP-SPR) technique. Biotinylated liposomes were bound onto an SPR gold chip surface coated with a streptavidin layer. The resulting MP-SPR signal proved the efficient binding of the liposomes. The thickness of the liposome layer calculated by modeling the MP-SPR signal was about 80 nm, which matched the average diameter of the liposomes. The mono-RL binding to the film of the phospholipid liposomes was monitored by SPR and the morphological changes of the liposome layer were assessed by modeling the SPR signal. We demonstrated the capacity of the MP-SPR technique to characterize the different steps of the liposome architecture evolution, i.e., from a monolayer of phospholipid liposomes to a single phospholipid bilayer induced by the interaction with mono-RLs. Further washing treatment with Triton X-100 detergent left a monolayer of phospholipid on the surface. As a possible practical application, our method based on a biomimetic membrane coupled to an SPR measurement proved to be a robust and sensitive analytical tool for the detection of mono-RLs with a limit of detection of 2 μg mL–1.

MP-SPR keywords: Au sensor slide, layer thickness, layer-by-layer modeling, liposome, refractive index