Biomimetic Vesicles with Designer Phospholipids Can Sense Environmental Redox Cues
Huseyin Erguven, Liming Wang, Bryan Gutierrez, Andrew H. Beaven, Alexander J. Sodt, Enver Çagrı Izgü
Abstract
High Resolution Image Download MS PowerPoint Slide Cell-like materials that sense environmental cues can serve as next-generation biosensors and help advance the understanding of intercellular communication. Currently, bottom-up engineering of protocell models from molecular building blocks remains a grand challenge chemists face. Herein, we describe giant unilamellar vesicles (GUVs) with biomimetic lipid membranes capable of sensing environmental redox cues. The GUVs employ activity-based sensing through designer phospholipids that are fluorescently activated in response to specific reductive (hydrogen sulfide) or oxidative (hydrogen peroxide) conditions. These synthetic phospholipids are derived from 1,2-dipalmitoyl- rac -glycero-3-phosphocholine and they possess a headgroup with heterocyclic aromatic motifs. Despite their structural deviation from the phosphocholine headgroup, the designer phospholipids (0.5–1.0 mol %) mixed with natural lipids can vesiculate, and the resulting GUVs (7–20 μm in diameter) remain intact over the course of redox sensing. All-atom molecular dynamics simulations gave insight into how these lipids are positioned within the hydrophobic core of the membrane bilayer and at the membrane–water interface. This work provides a purely chemical method to investigate potential redox signaling and opens up new design opportunities for soft materials that mimic protocells.