Murata Daiki, Tokunaga Satoshi, Tamura Tadashi, Kawaguchi Hiroaki, Miyoshi Noriaki, Fujiki Makoto, Nakayama Koichi, Misumi Kazuhiro
Veterinary Surgery, Department of Veterinary Clinical Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan.
Veterinary Teaching Hospital, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan.
J Orthop Surg Res. 2015 Mar 18;10:35. doi: 10.1186/s13018-015-0173-0.
Osteoarthritis (OA) is a major joint disease in humans and many other animals. Consequently, medical countermeasures for OA have been investigated diligently. This study was designed to examine the regeneration of articular cartilage and subchondral bone using three-dimensional (3D) constructs of adipose tissue-derived mesenchymal stem cells (AT-MSCs).
AT-MSCs were isolated and expanded until required for genetical and immunological analysis and construct creation. A construct consisting of about 760 spheroids that each contained 5.0 × 10(4) autologous AT-MSCs was implanted into an osteochondral defect (diameter: 4 mm; depth: 6 mm) created in the femoral trochlear groove of two adult microminipigs. After implantation, the defects were monitored by computed tomography every month for 6 months in animal no. 1 and 12 months in animal no. 2.
AT-MSCs were confirmed to express the premature genes and to be positive for CD90 and CD105 and negative for CD34 and CD45. Under specific nutrient conditions, the AT-MSCs differentiated into osteogenic, chondrogenic, and adipogenic lineages, as evidenced by the expressions of related marker genes and the production of appropriate matrix molecules. A radiopaque area emerged from the boundary between the bone and the implant and increased more steadily upward and inward for the implants in both animal no. 1 and animal no. 2. The histopathology of the implants after 6 months revealed active endochondral ossification underneath the plump fibrocartilage in animal no. 1. The histopathology after 12 months in animal no. 2 showed not only that the diminishing fibrocartilage was as thick as the surrounding normal cartilage but also that massive subchondral bone was present.
The present results suggest that implantation of a scaffold-free 3D construct of AT-MSCs into an osteochondral defect may induce regeneration of the original structure of the cartilage and subchondral bone over the course of 1 year, although more experimental cases are needed.
骨关节炎（OA）是人类和许多其他动物的主要关节疾病。因此，人们一直在积极研究针对OA的医学对策。本研究旨在使用脂肪组织来源的间充质干细胞（AT-MSCs）的三维（3D）构建体来检查关节软骨和软骨下骨的再生情况。
分离并扩增AT-MSCs，直至进行基因和免疫分析以及构建体创建所需。将一个由约760个球体组成的构建体植入两只成年微型猪股骨滑车沟中创建的骨软骨缺损处（直径：4毫米；深度：6毫米），每个球体包含5.0×10⁴个自体AT-MSCs。植入后，在动物1中每月通过计算机断层扫描监测缺损6个月，在动物2中监测12个月。
证实AT-MSCs表达早熟基因，CD90和CD105呈阳性，CD34和CD45呈阴性。在特定营养条件下，AT-MSCs分化为成骨细胞、软骨细胞和成脂细胞谱系，相关标记基因的表达和适当基质分子的产生证明了这一点。在动物1和动物2中，不透射线区域从骨与植入物的边界出现，并在植入物向上和向内的方向上更稳定地增加。动物1中6个月后植入物的组织病理学显示，丰满的纤维软骨下方有活跃的软骨内成骨。动物2中12个月后的组织病理学显示，不仅逐渐减少的纤维软骨与周围正常软骨一样厚，而且存在大量软骨下骨。
目前的结果表明，将AT-MSCs无支架3D构建体植入骨软骨缺损处可能在1年内诱导软骨和软骨下骨原始结构的再生，尽管还需要更多的实验案例。
