Upscaling Osteoclast Generation by Enhancing Macrophage Aggregation Using Hollow Microgels

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Osteoclasts are crucial for bone remodeling but challenging to study in vitro due to low yields of multinucleated cells.
• Existing methods for generating osteoclasts result in heterogeneous cultures, limiting research scalability.

Purpose of the Study:

• To investigate the potential of microencapsulating human macrophages in sacrificial tyramine-conjugated dextran (Dex-TA) microgels for generating homogeneous osteoclast populations.
• To assess the efficiency of osteoclast formation and purity within these 3D microenvironments compared to traditional 2D cultures.

Main Methods:

• Human mononuclear cells were isolated and differentiated into macrophages.
• Macrophages were encapsulated in microgels using flow-focus microfluidics and crosslinked.
• Encapsulated cells were differentiated into osteoclasts, and their morphology, viability, and fusion were analyzed.
• Microgels were degraded to enable cell sorting based on osteoclast marker expression.

Main Results:

• Successful encapsulation and differentiation of human macrophages into osteoclasts within Dex-TA microgels were achieved using high-throughput droplet microfluidics.
• Osteoclast formation was significantly higher in the 3D microgel environment compared to conventional 2D cultures.
• A method for establishing pure osteoclast cultures through cell release from degradable microgels was demonstrated.

Conclusions:

• Microencapsulation in Dex-TA microgels offers a scalable and efficient strategy for generating homogeneous multinucleated osteoclast cultures.
• This 3D culture system overcomes limitations of traditional 2D methods, facilitating robust osteoclast research.
• The developed technique enables the isolation of pure osteoclast populations for advanced studies in bone health and disease.