Feng Yong, Jin Xuhong, Dai Gang, Liu Jun, Chen Jiarong, Yang Liu
Center of Joint Surgery, Southwest Hospital, the Third Military Medical University, Chongqing, 400038, China.
Department of Orthopedics, Haikou Hospital, Xiangya Medical College, Central South University, Hainan, 570208, China.
J Huazhong Univ Sci Technolog Med Sci. 2011 Apr;31(2):204-209. doi: 10.1007/s11596-011-0253-2. Epub 2011 Apr 20.
To assess a novel cell manipulation technique of tissue engineering with respect to its ability to augment superparamagnetic iron oxide particles (SPIO) labeled mesenchymal stem cells (MSCs) density at a localized cartilage defect site in an in vitro phantom by applying magnetic force. Meanwhile, non-invasive imaging techniques were use to track SPIO-labeled MSCs by magnetic resonance imaging (MRI). Human bone marrow MSCs were cultured and labeled with SPIO. Fresh degenerated human osteochondral fragments were obtained during total knee arthroplasty and a cartilage defect was created at the center. Then, the osteochondral fragments were attached to the sidewalls of culture flasks filled with phosphate-buffered saline (PBS) to mimic the human joint cavity. The SPIO-labeled MSCs were injected into the culture flasks in the presence of a 0.57 Tesla (T) magnetic force. Before and 90 min after cell targeting, the specimens underwent T2-weighted turbo spin-echo (SET2WI) sequence of 3.0 T MRI. MRI results were compared with histological findings. Macroscopic observation showed that SPIO-labeled MSCs were steered to the target region of cartilage defect. MRI revealed significant changes in signal intensity (P<0.01). HE staining exibited that a great number of MSCs formed a three-dimensional (3D) cell "sheet" structure at the chondral defect site. It was concluded that 0.57 T magnetic force permits spatial delivery of magnetically labeled MSCs to the target region in vitro. High-field MRI can serve as an very sensitive non-invasive technique for the visualization of SPIO-labeled MSCs.
为了评估一种新型组织工程细胞操作技术，该技术通过施加磁力来增强超顺磁性氧化铁颗粒（SPIO）标记的间充质干细胞（MSCs）在体外模型中局部软骨缺损部位的密度。同时，使用非侵入性成像技术通过磁共振成像（MRI）追踪SPIO标记的MSCs。培养人骨髓间充质干细胞并用SPIO进行标记。在全膝关节置换术中获取新鲜退变的人骨软骨碎片，并在其中心制造软骨缺损。然后，将骨软骨碎片附着到装有磷酸盐缓冲盐水（PBS）的培养瓶侧壁上以模拟人体关节腔。在0.57特斯拉（T）磁力存在的情况下，将SPIO标记的MSCs注入培养瓶中。在细胞靶向之前和之后90分钟，对标本进行3.0 T MRI的T2加权快速自旋回波（SET2WI）序列检查。将MRI结果与组织学结果进行比较。宏观观察表明，SPIO标记的MSCs被引导至软骨缺损的目标区域。MRI显示信号强度有显著变化（P<0.01）。苏木精-伊红（HE）染色显示大量MSCs在软骨缺损部位形成三维（3D）细胞“片”结构。得出的结论是，0.57 T磁力允许在体外将磁性标记的MSCs空间递送至目标区域。高场MRI可作为一种非常敏感的非侵入性技术用于可视化SPIO标记的MSCs。
