Photo-Triggered Soft Materials With Differentiated Diffusive Pathways

Controlled diffusive transport between regions within a compartmentalized structure is an essential feature of cellular-inspired materials. Using the droplet interface bilayer (DIB) technique, biomolecular soft materials can be constructed in an oil medium by connecting multiple lipid-coated microdroplets together through interfacial bilayers. While traditionally achieved through the incorporation of pore forming toxins (PFTs), signal propagation within DIB assemblies can be remotely controlled through the integration of photopolymerizable phospholipids (23:2 DiynePC) into the aqueous phase. Since such strategy allows for the formation of UV-C triggered pathways only between droplets both containing DiynePC, polymerizable phospholipids have shown an advantage of reducing undesired diffusion and forming conductive pathways. The partial polymerization of lipid bilayers formed through the DIB platform is still to this date underexplored in the literature. In a previous work, we have shown that the incorporation of 23:2 DiynePC into lipid bilayers allows for the creation of patterned conductive pathways in a 2D DIB structure. The properties of photosensitive bilayers were also investigated but not their channel activity. The functionalization of bilayers-based photosensitive structures through transmembrane channels remains an under-investigated mean of achieving further differentiated conductive channels. This work explores the reconstitution of several transmembrane channels such as alpha-hemolysin (αHL) and alamethicin (ALM) into partially polymerized lipid bilayers. We believe that the ability to incorporate transmembrane channels into photosensitive DIB soft structures allows for further differentiation of signal propagation pathways by including both edge-defect induced pores as well as more traditional and bio-derived transporters.