Cell viability and protein composition in cryopreserved cartilage.

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Orthopedic Surgery

Background:

• Chondrocyte survival in frozen-stored osteochondral allografts is critically low.
• Current storage methods require optimization to maintain cartilage viability and extracellular matrix integrity.

Purpose of the Study:

• To evaluate the impact of different storage conditions on chondrocyte viability and extracellular protein content in osteochondral allografts.
• To determine optimal cryopreservation strategies for preserving articular cartilage.

Main Methods:

• Articular cartilage from sheep femoral condyles was stored at 4°C, -80°C, and -196°C with and without cryoprotective agents for 1 month.
• Cell viability was assessed, and Western blot analysis was performed for TGF-beta, IGF-1, and matrix metalloproteinases (MMPs).

Main Results:

• Storage at 4°C resulted in significantly decreased chondrocyte viability (36.2% to 48.1%).
• Transforming growth factor-beta (TGF-beta) and insulin-like growth factor-1 (IGF-1) decreased within the first week across all groups.
• Lower protease levels were observed in cartilage stored at -80°C and -196°C compared to 4°C storage.

Conclusions:

• Frozen storage of cartilage, particularly at 4°C, leads to reduced cell viability and elevated matrix metalloproteinases (MMPs), compromising graft quality.
• Modifying cryopreservation conditions holds potential for improving the viability and quality of preserved cartilage for allografts.