Droplet-based valveless microfluidic system for phage-display screening against spheroids

Area of Science:

• Biotechnology
• Microfluidics
• Biochemistry

Background:

• Spheroids mimic *in vivo* membrane protein presentation but are difficult to manipulate.
• Existing microfluidic systems face challenges with large spheroid passage and valveless flow control.

Purpose of the Study:

• To develop a droplet-based valveless microfluidic system for phage-display screening against spheroids.
• To enable automated binding, washing, eluting, and collecting processes for spheroids.
• To overcome limitations of manual spheroid manipulation and conventional microchannel valving.

Main Methods:

• Utilized a droplet-based valveless microfluidic system with active camera and pump control.
• Engineered microchannels with large cross-sections for spheroid passage.
• Implemented selective blocking and flush washing techniques for minimizing nonspecific binding.

Main Results:

• Demonstrated successful manipulation and processing of spheroids within the microfluidic system.
• Achieved efficient phage-display screening processes, including binding, washing, eluting, and collecting.
• Validated the system's capability to minimize nonspecific phage binding through selective blocking and flush washing.

Conclusions:

• The developed valveless microfluidic system effectively performs phage-display screening against spheroids.
• This technology offers a promising platform for studying *in vivo*-like membrane protein interactions.
• The system's design addresses key challenges in spheroid handling and microfluidic flow control.