Developmental dynamics mimicking inversely engineered pericellular matrix for articular cartilage regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Cellular Mechanics

Background:

• Mesenchymal stem cell (MSC) therapy for articular cartilage (AC) regeneration faces challenges due to mechanical mismatch with scaffolds.
• Existing scaffolds neglect the crucial role of the natural chondrocyte pericellular matrix (PCM).

Purpose of the Study:

• To investigate the temporal and spatial characteristics of collagen distribution around chondrocytes.
• To develop a scaffold system mimicking PCM to enhance MSC chondrogenesis and AC repair.
• To elucidate the signaling pathways involved in mechanotransduction during MSC differentiation.

Main Methods:

• Developed a layer-by-layer single-cell encapsulation system to mimic PCM.
• Investigated cellular micromechanical environments and employed full-atom simulations of TRPV4.
• Analyzed mRNA sequencing and spatial transcriptome data to identify signaling pathways.

Main Results:

• The engineered scaffold successfully mimicked PCM mechanical responses and collagen secretion patterns.
• Identified the TRPV4-YAP/TAZ-PI3K-Akt signaling pathway as critical for MSC cartilage formation.
• Demonstrated superior AC regeneration in a rat model using PCM-mimicking scaffolds compared to MSC-only scaffolds.

Conclusions:

• A PCM-mimicking scaffold system can significantly improve MSC chondrogenesis.
• This approach enhances the efficacy of MSC-based therapy for articular cartilage repair.
• The study highlights the importance of cellular mechanical coupling in tissue engineering.