Glyco-acrylate copolymers for bilayer tethering on benzophenone-modified substrates

Area of Science:

• Biophysics
• Materials Science
• Biotechnology

Background:

• Model biological membranes are vital for biophysical studies and device development.
• Solid-supported lipid bilayers often exhibit non-physiological interactions with substrates.
• A need exists for stable and robust membrane systems for advanced applications.

Purpose of the Study:

• To develop a polymer-tethered lipid bilayer system to mitigate non-physiological substrate interactions.
• To create a stable and robust model membrane system for demanding applications.
• To investigate the properties of a novel copolymer-lipid system for enhanced bilayer formation.

Main Methods:

• Synthesis of a random copolymer with lipid analogue anchors and a glyco-acrylate backbone.
• Photochemical coupling to covalently attach the copolymer to substrates.
• Langmuir isotherms, isobaric creep, and atomic force microscopy (AFM) for characterization.
• Fluorescence microscopy to monitor bilayer homogeneity and fluidity.

Main Results:

• Langmuir isotherms showed lipid chains dominating film behavior without significant phase transitions.
• Hysteresis experiments confirmed the absence of irreversible states during monolayer compression.
• AFM and fluorescence microscopy demonstrated the formation of fluid, homogeneous bilayers.
• A 5% copolymer system achieved continuous bilayers with high lateral diffusion coefficients (0.6 µm²/s).

Conclusions:

• The developed polymer-tethered lipid bilayer system offers enhanced stability and robustness.
• This system effectively minimizes non-physiological protein-substrate interactions.
• The characterized bilayers are suitable for fundamental biophysical studies and membrane-based device applications.