Engineering curvature: block copolymer lithography for the fabrication of curved lipid membranes and their impact on protein–membrane interactions †

Abstract

Studying biological membranes is essential for understanding key cellular processes such as signal transduction and ion transport, which have significant implications for developing advanced therapies for diseases like cancer and cardiovascular disorders. However, the structural complexity of these membranes presents challenges for detailed analysis, necessitating advanced techniques that are often incompatible with in-cell studies. As a result, current research has shifted toward fabricating artificial membranes that closely mimic their natural counterparts. A critical limitation remains in replicating the natural curvature of biological membranes that restricts the effectiveness of existing flat in vitro models. In response, this study introduces block copolymer (BCP) lithography as a method for creating nanostructured surfaces that induce controllable local membrane curvature. Lipid bilayer formation was confirmed using atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D). Subsequent investigations into clathrin assembly lymphoid myeloid-leukemia (CALM) protein interactions with curved membranes revealed a preferential binding to curved surfaces, characterized by a more homogeneous protein distribution compared to flat membranes. These findings enhance our understanding of membrane–protein interactions and cellular processes, opening up potential applications in drug delivery and biosensing.