Articular Cartilage Tissue Engineering: Cells, Bioinstructive Scaffolds, Immunological Microenvironment, and Emerging...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Articular cartilage has limited self-repair due to its avascular nature.
• Current treatments like marrow stimulation yield suboptimal fibrocartilage, while matrix-induced autologous chondrocyte implantation (MACI) has limitations.
• Tissue engineering offers potential for durable articular cartilage repair.

Purpose of the Study:

• To comprehensively review articular cartilage tissue engineering strategies.
• To benchmark existing therapies against novel approaches.
• To identify key factors for successful clinical translation.

Main Methods:

• Review of cellular, biomaterial, biochemical, and immunological aspects of cartilage tissue engineering.
• Analysis of mesenchymal stromal cells (MSCs) from various sources and their differentiation pathways.
• Evaluation of advanced scaffold designs and adjunct therapies like low-intensity pulsed ultrasound (LIPUS).

Main Results:

• Comparison of MACI with single-stage therapies highlights trade-offs in logistics and outcomes.
• Mesenchymal stromal cells (MSCs) show potential but require careful management to avoid hypertrophic drift.
• Bioinstructive scaffolds and adjunct therapies offer enhanced cartilage regeneration potential.
• Understanding the immunological interplay is crucial for construct success.

Conclusions:

• A multi-faceted approach integrating cell source, biomaterials, and immunological considerations is needed for effective cartilage repair.
• Standardized potency assays, immune-aware design, and long-term in vivo data are critical for clinical translation.
• Four translational tiers are proposed to clarify the evidence base for different strategies.