Long Term Efficacy of Cartilage Repair Induced By scSOX9 in Situ with Bone Marrow-Derived Mesenchymal Stem Cells

Zhang X; Wu S; Zhu Y; Chu CQ
Arthritis Rheumatol. 2018; 70 (suppl 10). Abstract Number 850

Les titres, résumés et légendes des publications sont présentés en anglais.

Background/Purpose: Microfracture induces fibrocartilage or fibro-hyaline cartilage both are biomechanically inferior to hyaline cartilage. We reported previously that a super positively charged SOX9 (scSOX9) improved the quality of microfracture induced cartilage repair by inducing mesenchymal stem cell differentiation into chondrocytes and promoting hyaline-like cartilage. Here we examined the long-term efficacy of cartilage repair induced by microfracture with scSOX9 by assessing biomechanical property of the repaired cartilage.

Methods: A cartilage defect was created at the right femoral trochlear groove in New Zealand female rabbits and microfracture was performed. scSOX9 was administered at the site of mcrofracture via a collagen membrane. Cartilage repair was assessed at 12 weeks by gross morphology, histology and matrix components. The distal femur was extirpated for biomechanical test.

Results: Cartilage defect in rabbits was treated with microfracture with collagen membrane only; with a SOX9 mutant, scSOX9-A76E or with scSOX9

respectively. Rabbits were observed for 12 weeks post-surgery. scSOX9 treated group induced hyaline-like cartilage while collagen-membrane only induced fibrocartilage and mutant scSOX9-A76E poorly induced cartilage repair. The cartilage matrix in scSOX9 treated group showed highly enriched

proteoglycan content. The thickness of repaired cartilage induced by scSOx9 was comparable to that of normal cartilage in the same area. Whereas, collagen membrane only induced a thinner layer of cartilage, and scSOX9-A76E treated group showed even worse repaired tissue. In consistent with the

histological data and the thickness of the repaired cartilage, the mechanical property of scSOX9 induced cartilage was also similar to that of normal cartilage (Figure 1).

Conclusion: This long term in vivo study demonstrated that when administered at the site of microfracture, scSOX9 was able to induce reparative tissue with features of hyaline cartilage and near normal biomechanical properties. scSOX9 induced cartilage repair was endurable in long term. Together, this technology has potential to translate into clinical use for cartilage repair to prevent progression to osteoarthritis.

Utilisation des équipements

L’étude évaluait le cartilage réparé après microfracture avec administration de scSOX9 dans des défauts de la trochlée fémorale chez le lapin. Les fémurs distaux ont été prélevés pour des essais biomécaniques du tissu réparé. Le résumé disponible ne précise ni l’instrument, ni la mesure mécanique, ni le protocole de chargement; un rôle du Mach-1 Mechanical Tester en indentation ne peut donc être vérifié.