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Balancing Permeability and Stability: A Study of Hybrid Membranes for Synthetic Cells Using Lipids and PBd-b-PEO Block Copolymers

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide We have synthesized hybrid membranes composed of amphiphilic block copolymers, polybutadiene–poly(ethylene oxide) [PBd- b -PEO], with different lengths [PBd 22 -PEO 14 and PBd 11 -PEO 8 ] and mixtures of phospholipids (DOPC:DOPG:DOPE 50:25:25 mol %) to combine the properties of both in terms of stability and fluidity of the membrane. The amphiphilic block copolymers increase the stability, whereas the lipids support the functionality of membrane proteins. The hybrid nature of the bilayers was studied by means of Cryo-TEM, Langmuir–Blodgett technique, atomic force microscopy (AFM), electrical measurements, and fluorescence-based stopped-flow assay to determine the permeability of the membrane for water and osmolytes. We observe that the structural, thermodynamic, and permeability properties of hybrid PBd 11 -PEO 8 membranes are similar to their purely lipid counterparts, with the advantage of being more stable and resisting a higher transmembrane electrical potential. Hybrid membranes with the longer polymer, PBd 22 -PEO 14, display more significant structural, thermodynamic, and permeability differences and show less favorable properties than hybrid-PBd 11 -PEO 8 membranes.

Source: Biomacromolecules

DOI: 10.1021/acs.biomac.4c01651