The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and the Key Laboratory of Oral Biomedicine Ministry of Education, and Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, People's Republic of China.
The Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
Adv Wound Care (New Rochelle). 2021 Aug;10(8):401-414. doi: 10.1089/wound.2019.1140. Epub 2020 Dec 18.
Osteochondral defect presents a big challenge for clinical treatment. This study aimed at constructing a bi-layered composite chitosan/chitosan-β-tricalcium phosphate (CS/CS-β-TCP) scaffold and at repairing the rat osteochondral defect. The bi-layered CS/CS-β-TCP scaffold was fabricated by lyophilization, and its microstructure was observed by a scanning electron microscope. Chondrocytes and bone marrow stem cells (BMSCs) were seeded into the CS layer and the CS-β-TCP layer, respectively. Viability and proliferation ability of the cells were observed under a confocal microscope. After subcutaneous implantation, the chondrogenic ability of the CS layer and osteogenic ability of the CS-β-TCP layer were evaluated by immunofluorescence. Then, the bi-layered scaffolds were implanted into the rat osteochondral defects and the harvested samples were macroscopically and histologically evaluated. The bi-layered CS/CS-β-TCP scaffold exhibited the distinctive microstructures for each layer. The seeded chondrocytes in the CS layer could maintain the chondrogenic lineage, whereas BMSCs in the CS-β-TCP layer could continually differentiate into the osteogenic lineage. Moreover, cells in both layers could maintain well viability and excellent proliferation ability. For the study, the newly formed tissues in the bi-layered scaffolds group were similar with the native osteochondral tissues, which comprised hyaline-like cartilage and subchondral bone, with better repair effects compared with those of the pure CS group and the blank control group. This is the first time that the bi-layered composite CS/CS-β-TCP scaffold has been fabricated and evaluated with respect to osteochondral defect repair. The bi-layered CS/CS-β-TCP scaffolds could facilitate osteochondral defect repair and might be the promising candidates for osteochondral tissue engineering.
软骨下骨缺损的临床治疗仍是一个巨大的挑战。本研究旨在构建一种双层壳聚糖/壳聚糖-β-磷酸三钙（CS/CS-β-TCP）复合支架，并用于修复大鼠的软骨下骨缺损。双层 CS/CS-β-TCP 支架是通过冷冻干燥法制备的，并通过扫描电子显微镜观察其微观结构。将软骨细胞和骨髓基质干细胞（BMSCs）分别接种到 CS 层和 CS-β-TCP 层。通过共聚焦显微镜观察细胞的活力和增殖能力。皮下植入后，通过免疫荧光评估 CS 层的软骨形成能力和 CS-β-TCP 层的成骨能力。然后，将双层支架植入大鼠软骨下骨缺损模型中，对收获的样本进行宏观和组织学评估。双层 CS/CS-β-TCP 支架呈现出各层独特的微观结构。CS 层中的接种软骨细胞可以保持软骨细胞系，而 CS-β-TCP 层中的 BMSCs 可以持续分化为成骨细胞系。此外，两层中的细胞都可以保持良好的活力和优异的增殖能力。在本研究中，双层支架组的新形成组织与天然软骨下骨组织相似，包含透明软骨样软骨和软骨下骨，与纯 CS 组和空白对照组相比，修复效果更好。这是首次制备和评估双层复合 CS/CS-β-TCP 支架用于软骨下骨缺损修复。双层 CS/CS-β-TCP 支架可以促进软骨下骨缺损的修复，可能是软骨组织工程有前途的候选材料。
