Integrated Microfluidic Chip Enabling Preparation and Immobilization of Cell-Laden Microspheres, and...

Area of Science:

• Biotechnology
• Microfluidics
• Cell Biology

Background:

• Microfluidic preparation of cell-laden hydrogel microspheres is crucial for single-cell analysis.
• Current methods separate microsphere preparation from cell culture, risking contamination and hindering observation.
• Conventional techniques are reagent-intensive and lead to microsphere stacking.

Purpose of the Study:

• To develop an integrated microfluidic chip for seamless cell encapsulation, microsphere formation, and on-chip cell culture.
• To overcome limitations of separate preparation and culture processes, reducing contamination and improving cell observation.
• To enable automated, high-throughput analysis of single or few cells within hydrogel microspheres.

Main Methods:

• Fabrication of an integrated microfluidic chip using polydimethylsiloxane (PDMS).
• Utilized a biocompatible fluorinated oil and a sodium alginate-calcium ion gelation system for microsphere preparation.
• Sequential droplet generation with cell encapsulation, gel solidification, microsphere trapping, and on-chip culture.

Main Results:

• Achieved uniform hydrogel microspheres with a size uniformity coefficient of variation (CV) of 3.85%.
• Demonstrated a single-cell encapsulation efficiency of 33.8% ± 1.8% for K562 cells.
• Maintained >95% cell viability after 24 hours of culture in 286 independent on-chip chambers.

Conclusions:

• The integrated microfluidic chip successfully combines microsphere preparation and 3D cell culture, minimizing contamination.
• The system facilitates automated workflows, reduces reagent consumption, and improves single-cell observation.
• This approach offers a significant advancement for large-scale comparative analysis of single or few cells.