Preferential Membrane Remodeling on Curved Biointerfaces Induced by Conjugated Oligoelectrolyte

Conjugated oligoelectrolytes (COEs) spontaneously intercalate into and modulate lipid membranes thanks to their hydrophobic backbone and hydrophilic ionic termini, enabling applications in biosensing, fluorescence imaging, antimicrobial therapy, and bioelectrochemical devices. While COE-membrane interactions are fundamental to their functionality, the intimate details of how COEs interact with membranes remain underexplored, particularly the influence of membrane shape–a defining feature of subcellular organelles that significantly influences the spatial organization and behavior of membrane-associated molecules. This study introduces a curved biointerface comprising vertical nanostructure arrays and supported lipid bilayers (SLBs) to investigate how membrane shape affects the COE-bilayer interaction. The curved SLB, following the predefined shapes of the nanobar array, mimics the natural curvature of subcellular membranes. Interestingly, the COE intercalation preferentially induces distinct membrane remodeling patterns from curved regions, i.e., tubes and patches linking to the nanobars, but not the adjacent flat membranes. The pattern morphology and stability alter with COE concentration changes and are sensitive to lipid composition. COE species with higher hydrophobicity provide more persistent remodeling over time. This study highlights the significance of membrane shape in COE-membrane interactions and validates the nanobar-curved membrane biointerface as a powerful platform to uncover mechanisms of membrane intercalation and modulation by membrane-specific compounds.