Engineering and development of model lipid membranes mimicking the HeLa cell membrane

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2021-12, Vol.630, p.127663, Article 127663
• Main Authors: Botet-Carreras, Adrià, Montero, M. Teresa, Sot, Jesús, Domènech, Òscar, Borrell, Jordi H.
• Format: Article
• Language: English
• Subjects: Atomic force microscopy (AFM); Förster resonance energy transfer (FRET); HeLa lipid bilayer models; Microviscosity
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2021.127663

Cells are complex systems whose interaction with nanocarriers, i.e., liposomes, are continuously under investigation to improve drug uptake. Model membranes can facilitate the understanding of the processes involved in fusion or endocytosis. In this work, we engineered two different lipid model membranes, vesicles and supported lipid bilayers (SLBs), mimicking the lipid composition of the HeLa cell plasma membrane. We characterized the model using atomic force microscopy (AFM) and fluorescence. We found that liposomes formed with four lipid components mimicking the HeLa cell bilayer show a liquid ordered fluid nature between 13 °C and 34 °C and yield featureless SLBs onto mica. We evaluated the fusion between the model and liposomes positively charged with and without cholesterol by AFM-based force spectroscopy and fluorescence techniques, such as Förster resonance energy transfer, fluorescence lifetime decay and fluorescence anisotropy. The results indicated a primary electrostatic interaction between the HeLa bilayer model and the liposomes. It was also confirmed the well-known fact that cholesterol enhances the fusion process with the engineered HeLa bilayer. All results support the usefulness of the engineered model in the rationale design of liposomes for drug delivery. We formed liposomes mimicking the composition of the HeLa cell membrane using POPC, POPE, POPS and cholesterol. We studied the fusion of engineered liposomes of POPC:DOTAP with or without cholesterol with two model membranes mimicking the HeLa cell membrane: i) a flat model characterised by AFM after formation of supported lipid bilayers, and b) a vesicle model characterised by FRET fluorescence. [Display omitted] •A lipid bilayer mimicking the HeLa membrane cell is characterised.•HeLa-mimicking liposomes show phase coexistence at room temperature.•Laterally segregated domains are not observed by AFM in Supported Lipid Bilayers.•Fusion of liposomes changes Young’s modulus of HeLa-mimicking bilayers.•POPC:DOTAP and POPC:CHOL:DOTAP liposomes fusing process with HeLa- mimicking bilayers is characterised by FRET fluorescence.•Changes in liposomes microviscosity and fluorescence lifetime corroborate the fusion process.