Stable supported lipid bilayers on zirconium phosphonate surfaces

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biophysics

Background:

• Supported lipid bilayers (SLBs) are crucial for mimicking cell membranes in biophysical and biomedical research.
• Existing methods for creating SLBs often face limitations in stability and substrate compatibility.

Purpose of the Study:

• To engineer robust and versatile supported lipid bilayers for studying protein-membrane interactions.
• To demonstrate a novel surface modification technique for creating stable SLBs on diverse substrates.

Main Methods:

• Utilized a zirconium phosphonate monolayer to create a reactive surface for tethering lipid bilayers via covalent bonds.
• Employed vesicle fusion for forming both symmetric and asymmetric lipid bilayers.
• Characterized membrane formation and stability using surface plasmon resonance enhanced ellipsometry (SPREE).
• Assessed membrane fluidity with fluorescence recovery after photobleaching (FRAP).

Main Results:

• Achieved stable, dehydration-resistant supported lipid bilayers with 10% phosphatidic acid.
• Obtained uniform, mobile lipid bilayers with diffusion coefficients around 4 µm²/s.
• Measured kinetic parameters for melittin binding to asymmetric lipid bilayers, showing comparable results to existing studies.

Conclusions:

• Supported lipid bilayers on zirconium phosphonate surfaces offer a highly stable and versatile biomimetic system.
• The method is applicable to various substrates (glass, gold, silicon, plastic) without requiring synthetic biomolecule modifications.
• This approach provides a reliable platform for advanced studies of protein-membrane interactions.