Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Center for Preventive Medical Sciences, Musculoskeletal Disease, Chiba University, Chiba, Japan.
Cartilage. 2020 Jan;11(1):122-129. doi: 10.1177/1947603518786542. Epub 2018 Jul 10.
We investigated the effect of administration of intra-articular mesenchymal stem cells (MSCs) on cartilage repair at different timings, and the distribution of MSCs in the knee.
A partial thickness cartilage defect (PTCD) was created on the medial femoral condyle in 14-week-old Sprague-Dawley rats. Intra-articular injection of 1 × 10 MSCs was performed at 3 time points, namely at the time of surgery (0w group), at 1 week after surgery (1w group), and at 2 weeks after surgery (2w group). For the control, 50 μL phosphate-buffered saline was injected at the time of surgery. The femoral condyles were collected at 6 weeks after creation of PTCD and assessed histologically. To investigate the distribution of MSCs, fluorescent-labeled MSCs were injected into the knee joint.
In the control group, the cartilage lesion was distinguishable from surrounding cartilage. In the 0w group, hypocellularity and a slight decrease in safranin O stainability were observed around the injured area, but cartilage was restored to a nearly normal condition. In contrast, in the 1w and 2w groups, the cartilage surface was irregular and safranin O stainability in the injured and surrounding areas was poor. Histological score in the 0w group was significantly better than in the control, 1w, and 2w groups. At 1 day postinjection, fluorescent-labeled MSCs were mostly distributed in synovium. However, no migration into the PTCD was observed.
Early intra-articular injection of MSCs was effective in enhancing cartilage healing in a rat PTCD model. Injected MSCs were distributed in synovium, not in cartilage surrounding the PTCD.
研究关节内间充质干细胞（MSCs）在不同时间点给药对软骨修复的影响，以及 MSCs 在膝关节中的分布。
在 14 周龄 Sprague-Dawley 大鼠的股骨内侧髁上造成部分厚度软骨缺损（PTCD）。在手术时（0w 组）、手术后 1 周（1w 组）和手术后 2 周（2w 组）时，对关节内注射 1×10 MSCs 进行了 3 次。作为对照，在手术时注射 50 μL 磷酸盐缓冲液。在 PTCD 形成后 6 周，收集股骨髁并进行组织学评估。为了研究 MSCs 的分布，将荧光标记的 MSCs 注射到膝关节中。
在对照组中，软骨损伤与周围软骨明显不同。在 0w 组中，损伤区域周围观察到细胞减少和番红 O 染色轻度减少，但软骨恢复到接近正常状态。相比之下，在 1w 和 2w 组中，软骨表面不规则，损伤和周围区域的番红 O 染色不佳。0w 组的组织学评分明显优于对照组、1w 组和 2w 组。注射后 1 天，荧光标记的 MSCs 主要分布在滑膜中。然而，没有观察到向 PTCD 的迁移。
关节内早期注射 MSCs 可有效增强大鼠 PTCD 模型中的软骨愈合。注射的 MSCs 分布在滑膜中，而不在 PTCD 周围的软骨中。
