Enzymatic outside-in cross-linking enables single-step microcapsule production for high-throughput three-dimensional...

Area of Science:

• Biomaterials Science
• Microfluidics
• Tissue Engineering

Background:

• Cell-laden hydrogel microcapsules are crucial for high-throughput production of cell aggregates used in 3D tissue engineering and drug screening.
• Existing methods face limitations in throughput, complexity, and biomaterial compatibility.

Purpose of the Study:

• To present a single-step microfluidic process for producing single-core microcapsules.
• To demonstrate a physically controlled enzymatic cross-linking method for improved shell formation.
• To enhance reproducibility, operational window, and throughput compared to conventional methods.

Main Methods:

• Utilized microfluidics for controlled production of single-core microcapsules.
• Employed enzymatic outside-in cross-linking of tyramine-conjugated polymers.
• Incorporated a silicone delay line for precise control over initiator diffusion and droplet retention time.

Main Results:

• Achieved predictable control over microcapsule cross-linking density and shell thickness via droplet retention time and flow rate.
• Demonstrated facile and cytocompatible production of cell-laden microcapsules.
• Enabled formation and isolation of long-term viable cellular spheroids.

Conclusions:

• The presented single-step, physically controlled enzymatic cross-linking method offers a significant advancement in microcapsule production.
• This technique is highly compatible with cell encapsulation and spheroid formation for advanced applications.
• The method improves key parameters like reproducibility and throughput for cell aggregate generation.