Switchable Lipid Provides pH-Sensitive Properties to Lipid and Hybrid Polymer/Lipid Membranes

Victor Passos Gibson (1) , Martin Fauquignon (2, 3) , Emmanuel Ibarboure (2, 3) , Jeanne Leblond Chain (1, 4) , Jean-François Le Meins (2, 3)

1 Gene Delivery Laboratory
2 LCPO - Laboratoire de Chimie des Polymères Organiques
3 Team 3 LCPO : Polymer Self-Assembly & Life Sciences
4 ARNA - Acides Nucléiques : Régulations Naturelle et Artificielle

Blending amphiphilic copolymers and lipids constitutes a novel approach to combine the advantages of polymersomes and liposomes into a new single hybrid membrane. Efforts have been made to design stimuli-responsive vesicles, in which the membrane’s dynamic is modulated by specific triggers. In this investigation, we proposed the design of pH-responsive hybrid vesicles formulated with poly(dimethylsiloxane)-block-poly(ethylene oxide) backbone (PDMS36-b-PEO23) and cationic switchable lipid (CSL). The latter undergoes a pH-triggered conformational change and induces membrane destabilization. Using confocal imaging and DLS measurements, we interrogated the structural changes in CSL-doped lipid and hybrid polymer/lipid unilamellar vesicles at the micro- and nanometric scale, respectively. Both switchable giant unilamellar lipid vesicles (GUV) and hybrid polymer/lipid unilamellar vesicles (GHUV) presented dynamic morphological changes, including protrusions and fission upon acidification. At the submicron scale, scattered intensity decreased for both switchable large unilamellar vesicles (LUV) and hybrid vesicles (LHUV) under acidic pH. Finally, monitoring the fluorescence leakage of encapsulated calcein, we attested that CSL increased the permeability of GUV and GHUV in a pH-specific fashion. Altogether, these results show that switchable lipids provide a pH-sensitive behavior to hybrid polymer/lipid vesicles that could be exploited for the triggered release of drugs, cell biomimicry studies, or as bioinspired micro/nanoreactors.

Mots clés: hybrid polymer/lipid membrane; pH-sensitive liposomes; switchable lipid; giant unilamellar vesicles; giant hybrid polymer/lipid vesicles; responsive vesicles

Domaines: Polymères; Matériaux; Matière Molle [cond-mat.soft]

Victor Passos Gibson, Martin Fauquignon, Emmanuel Ibarboure, Jeanne Leblond Chain, Jean-François Le Meins. Switchable Lipid Provides pH-Sensitive Properties to Lipid and Hybrid Polymer/Lipid Membranes. Polymers, 2020, 12 (3), pp.637. ⟨10.3390/polym12030637⟩. ⟨hal-02506021⟩