Biomimetic Vesicles with Designer Phospholipids Can Sense Environmental Redox Cues

Area of Science:

• Synthetic Biology and Biomaterials
• Chemical Sensing and Biosensors
• Soft Matter Physics and Chemistry

Background:

• Cell-like materials (protocells) are crucial for next-generation biosensors and understanding intercellular communication.
• Bottom-up engineering of protocells from molecular components presents significant challenges for chemists.
• Environmental redox cues play a vital role in cellular signaling pathways.

Purpose of the Study:

• To develop biomimetic lipid membranes capable of sensing environmental redox cues.
• To create synthetic phospholipids for activity-based sensing of reductive and oxidative conditions.
• To provide a purely chemical method for investigating redox signaling in engineered protocell models.

Main Methods:

• Fabrication of giant unilamellar vesicles (GUVs) using designer phospholipids mixed with natural lipids.
• Utilizing fluorescently activated synthetic phospholipids for activity-based redox sensing.
• Employing all-atom molecular dynamics simulations to analyze lipid positioning within the membrane bilayer.

Main Results:

• Designer phospholipids, despite structural deviations, successfully formed intact GUVs (7-20 μm) with natural lipids.
• The synthesized GUVs demonstrated fluorescent activation in response to specific reductive (H2S) and oxidative (H2O2) conditions.
• Molecular dynamics simulations provided insights into the membrane integration and interfacial behavior of the designer phospholipids.

Conclusions:

• A novel, purely chemical method was established for creating redox-responsive protocell mimics.
• The developed GUVs serve as effective biosensors for environmental redox conditions.
• This work opens new avenues for designing soft materials that mimic protocell functions and study redox signaling.