Characterization of biomimetic membranes formed from amphiphilic block copolymers assembled at oil-water interfaces*

The droplet interface bilayer (DIB) is a model membrane technique that leverages aqueous compartments submerged in oil to form lipid membrane-divided functional materials, with comparable hierarchal architectures and diverse functionalities to natural cells and tissues. Instead of using lipids, amphiphilic block copolymers (ABCs) that can assemble into lamellar structures enable alternative membrane compositions that have greater mechanical and chemical tunability. Poly(butadiene -b- poly(ethylene oxide) (PBPEO) with molecular weights c.a. 1 kDa is of specific interest as it forms biomimetic membranes capable of hosting integral membrane proteins. Yet, its use in DIBs and tissue-like materials has been limited to membranes containing both lipids and ABCs. Thus, the effects that ABC molecular weight, concentration, and oil selection have on the self-assembly of PBPEO-stabilized DIBs are not well understood. Preliminary results indicate that varying the molecular weights of the polymer and the alkane oils in which they are dissolved affects bilayer thinning and therefore membrane adhesion due to differing amounts of polymer chain swelling. The objectives of this work thus aim to characterize the stability, adhesion, morphology, and selective transport properties of non-lipid amphiphile interfacial membranes through pendant drop interfacial tensiometry, electrophysiology characterization, and imaging of PBPEO-coated adhesive droplets.