Engineering High-Quality Cartilage Microtissues Using Hydrocortisone Functionalized Microwells.

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Engineering clinically relevant, human-scale musculoskeletal tissues remains a significant challenge.
• Scaffold-free, developmentally inspired approaches show promise for cartilage tissue engineering but face limitations in scaling up.
• Modular biofabrication using microtissues as building blocks requires robust differentiation of mesenchymal stem/stromal cells (MSCs).

Purpose of the Study:

• To develop a method for manufacturing scalable, scaffold-free cartilage microtissues.
• To identify factors enhancing chondrogenic differentiation of MSCs within microwell arrays.
• To establish a platform for generating high-quality microtissue building blocks for larger engineered tissues.

Main Methods:

• Utilized novel microwell array stamps for rapid and reliable generation of cartilage microtissues.
• Investigated the role of Endothelial Growth Medium (EGM) in enhancing MSC aggregation and chondrogenesis.
• Identified key soluble factors within EGM responsible for improved MSC chondrogenic capacity.

Main Results:

• Successfully manufactured cartilage microtissues at various scales using the developed microwell system.
• Discovered that hydrocortisone is the primary factor in EGM that significantly enhances MSC chondrogenic capacity.
• Demonstrated the generation of numerous high-quality, extracellular matrix-rich cartilage microtissues from heterogeneous MSC populations.

Conclusions:

• A simple and potent method using hydrocortisone was established for improving MSC chondrogenesis in scaffold-free microtissues.
• This strategy enables the generation of scalable engineered cartilage by ensuring high-quality microtissue building blocks.
• The findings support the advancement of modular biofabrication strategies for creating large-scale cartilage tissues.