Multi-size spheroid formation using microfluidic funnels

Area of Science:

• Biotechnology
• Microfluidics
• 3D Cell Culture

Background:

• Spheroid formation is crucial for 3D biological assays and drug discovery.
• Existing methods for spheroid generation often lack precise size control and automation.
• Microfluidic platforms offer potential for improved spheroid production but require further development.

Purpose of the Study:

• To develop an automated microfluidic platform for generating multi-size spheroids with controlled cell seeding.
• To introduce technological innovations for enhanced cell seeding control and independent droplet manipulation.
• To enable on-chip formation, treatment, staining, and imaging of spheroids for streamlined analysis.

Main Methods:

• A novel microfluidic chip design utilizing a
• microfluidic funnel
• layer for precise cell metering.
• Single inlet loading with constant cell concentration for reproducible spheroid generation.
• Hydrophobic polydimethylsiloxane (PDMS) surface for device stability and long-term storage.

Main Results:

• Achieved enrichment factors up to 37× for precise cell seeding.
• Successfully generated viable spheroids with diameters ranging from 230-420 μm (OV90) and 280-530 μm (TOV112D).
• Demonstrated the platform's capability for on-chip spheroid formation, treatment, and analysis.

Conclusions:

• The developed microfluidic platform with microfluidic funnels enables automated, size-controlled spheroid formation.
• This technology, termed single inlet multi-size spheroid (SIMSS) chips, is suitable for 3D biological assays requiring size-dependent responses.
• Potential applications include chemoresponse assays, photodynamic therapy, and drug transport characterization in drug discovery.