3D Bioprinted Integrated Osteochondral Scaffold-Mediated Repair of Articular Cartilage Defects in the Rabbit Knee

Objective To demonstrate that a 3D-bioprinted integrated osteochondral scaffold can provide improved repair of articular cartilage defects in the rabbit knee compared to that reported for traditional tissue-engineering methods. Results Bone marrow mesenchymal stem cells were differentiated into osteoblasts and chondrocytes as seed cells and mixed with the corresponding bone and cartilage scaffold materials. An integrated osteochondral biphasic scaffold was fabricated via 3D-bioprinting technology through successive natural overlays of the printed material and used to repair full-thickness articular cartilage defects in the rabbit knee. Histological and biomechanical assessment of repaired tissue at 6 months post-transplantation showed almost complete repair of injured articular surfaces and presence of hyaline cartilage. A boundary existed between the transition and repair zones. The Wakitani histological score was 5.50 ± 2.07 points; maximum load was 183.11 ± 35.20 N. Repaired cartilage was integrated firmly with the subchondral bone and almost assimilated with surrounding cartilage and bone tissues. Conclusion The 3D bioprinted integrated osteochondral scaffold achieved double bionic effects on the scaffold composition and structure, and it is expected to offer a new strategy for articular cartilage repair and regeneration.