Speaker
Description
Background
Critical-size bone defects (CSDs), resulting from trauma, infection, or tumor resection, pose significant clinical challenges. Autologous bone grafting has limitations like donor site morbidity, necessitating novel strategies. Approaches mimicking endochondral ossification, crucial for bone development and healing, show promise for bone regeneration. Many studies involve seeding mesenchymal stem cells onto scaffolds and subsequently inducing chondrogenesis of these cell-scaffold constructs. However, exogenous scaffolds risk complications like chronic inflammation. This study aimed to develop a novel CSD therapy using scaffold-free cartilage constructs from rat adipose-derived stromal/stem cells (rADSCs).
Material Method
A bio-3D printer fabricated these scaffold-free constructs by stacking cell spheroids. Scaffold-free cartilage constructs from rADSCs underwent chondrogenic induction. A 5-mm CSD was created in rat femurs. Three groups (n=24) were: Defect (no implant), ADSC (undifferentiated constructs), and ADSC-Ch (chondrogenically induced constructs). CT and histological analyses were performed at 6 and 12 weeks post-implantation.
Result
CT at 6 and 12 weeks showed significantly higher Bone Volume/Total Volume in the ADSC-Ch group versus ADSC and Defect groups (p<0.01). No significant difference was observed between the ADSC and Defect groups. Histological scoring at both 6 and 12 weeks revealed that the ADSC-Ch group achieved significantly higher scores compared to both the Defect and ADSC groups (p<0.05), while no significant difference was noted between the Defect and ADSC groups. Regarding specific tissue findings, the ADSC-Ch group exhibited robust formation of new cortical and cancellous bone, continuous with native bone margins and leading to bony bridging. In contrast, new bone formation in the Defect and ADSC groups was confined to the defect periphery, with central areas predominantly filled by adipose and fibrous tissues.
Conclusion
These findings show rADSC-derived scaffold-free cartilage constructs effectively promote CSD healing in rats. This scaffold-free approach mimicking endochondral ossification holds promise for clinical use, avoiding scaffold-related complications. However, further studies in larger animal models are needed.
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