Repairing a critical cranial defect using WISP1-pretreated chondrocyte scaffolds

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Orthopedic Surgery

Background:

• Cranial fractures with extensive bone loss often require surgical intervention using autologous bone grafts.
• Current grafting methods can lead to donor site morbidity.
• Cartilage presents a potential alternative autologous source for promoting cranial fracture repair due to its avascular and aneural properties.

Purpose of the Study:

• To investigate the potential of using autologous chondrocytes, particularly WISP1-primed chondrocytes, to promote repair in critical cranial defects.
• To evaluate the efficacy of chondrocyte-seeded collagen scaffolds in a rat calvaria defect model.

Main Methods:

• In vitro induction of cartilage mineralization using primary chondrocytes with BMP2 and/or WISP1.
• Evaluation of chondrocyte-seeded collagen scaffolds for expression profiles and alkaline phosphatase (ALP) activity in vitro.
• Implantation of WISP1-pretreated chondrocytes (WCS) and untreated chondrocytes (UCS) in a Lewis rat 8 mm critical calvaria defect model.
• In vivo monitoring using live CT and post-sacrifice analysis via microCT, histology, and serum markers.

Main Results:

• WISP1 administration in micromass cultures showed an osseous inducing trend, maintained in chondrocyte-seeded scaffolds.
• In vivo, both UCS and WCS groups demonstrated higher mineralization volumes compared to controls.
• WCS group exhibited enhanced anabolic bone formation and structural improvements, with trabecular bone detected in both WCS and UCS groups.

Conclusions:

• Autologous chondrocytes effectively expedite the formation of native-like osseous tissue in critical cranial defects.
• WISP1 priming of chondrocytes in culture further enhances bone formation and repair.
• This approach supports the use of autologous chondrocytes for repairing critical maxillofacial defects, potentially reducing donor site morbidity.