Using a patterned grating structure to create lipid bilayer platforms insensitive to air bubbles.

Area of Science:

• Biomembrane science
• Microfluidics
• Biosensor development

Background:

• Supported lipid bilayers (SLBs) are vital for biosensing due to their native lipid orientation and fluidity.
• Microfluidic integration offers efficient reagent handling but risks SLB damage from air bubbles.
• Existing methods to protect SLBs involve chemical modifications or protective layers.

Purpose of the Study:

• To develop a physical method for protecting supported lipid bilayers (SLBs) in microfluidic devices from air bubbles.
• To investigate the effectiveness of patterned obstacle gratings in preventing SLB destruction.
• To ensure preserved membrane fluidity and biomolecular interaction capabilities after air bubble exposure.

Main Methods:

• Fabrication of microfluidic channels with patterned obstacle gratings.
• Testing SLB stability under air bubble exposure with varying grating geometries and air bubble speeds.
• Assessing the interaction ability of receptors within protected SLBs using streptavidin-biotinylated lipid assays.

Main Results:

• Patterned obstacle gratings successfully protected SLBs from air bubble damage by trapping water.
• The required obstacle distance for protection decreased with increased air bubble speed.
• SLBs retained high membrane fluidity and receptor interaction capabilities after air bubble treatment.

Conclusions:

• The developed microfluidic platform with patterned obstacles provides robust physical protection for SLBs against air bubbles.
• This approach simultaneously preserves membrane fluidity and accessibility, overcoming previous limitations.
• The platform enables highly stable in vitro cell-membrane-related bioassays when integrated with surface analytical tools.