Bioinspired scaffold recapitulating chondrogenic ontogeny and microenvironment for functional cartilage regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedics

Background:

• Focal articular cartilage defects are a major cause of osteoarthritis, a significant global health issue.
• Current treatments are limited by a lack of understanding of cartilage development and microenvironment regulation.
• Developing effective strategies for cartilage repair is crucial for improving patient outcomes.

Purpose of the Study:

• To develop and evaluate a novel biomimetic scaffold that recapitulates native cartilage ontogeny for effective focal cartilage defect repair.
• To investigate the cellular and molecular mechanisms underlying scaffold-mediated cartilage regeneration.
• To assess the potential of the scaffold as a therapeutic strategy for osteoarthritis.

Main Methods:

• Development of a tri-layer scaffold (CE-SKP/CPH/P2G3) designed to mimic cartilage developmental stages.
• In vitro characterization of scaffold properties (porosity, swelling, degradation, biocompatibility).
• In vivo implantation in a cartilage defect model, followed by histological analysis and single-cell RNA sequencing (scRNA-seq).

Main Results:

• The tri-layer scaffold successfully promoted the regeneration of both cartilage and calcified cartilage in vivo, restoring native articular cartilage structure within 24 weeks.
• In vitro studies confirmed optimal scaffold properties for sequential cell recruitment, differentiation, and mineralization.
• ScRNA-seq identified stem cells from bone marrow (SMSCs) and a novel chondrocyte subpopulation (CHON_5) as key players in cartilage repair, with FGF signaling mediating their communication.

Conclusions:

• The developed biomimetic tri-layer scaffold effectively repairs focal cartilage defects by emulating natural cartilage development and microenvironmental cues.
• The scaffold facilitates functional cartilage regeneration by orchestrating SMSC recruitment, chondrogenesis, and hypertrophic calcification.
• This innovative approach holds significant promise for the treatment of osteoarthritis and the restoration of articular cartilage function.