Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
Department of Thyroid and Breast Surgery, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
Stem Cell Res Ther. 2021 Feb 17;12(1):143. doi: 10.1186/s13287-021-02207-x.
Intervertebral fusion is the most common surgery to treat lumbar degenerative disease (LDD). And the graft material used in the operation is derived from the iliac crest to promote fusion. However, autografts possess the fatal disadvantage of lack of source. Therefore, economical and practical bone substitutes are urgently needed to be developed. Sinusoidal electromagnetic fields (EMF) combined with tissue engineering techniques may be an appropriate way to promote intervertebral fusion.
In this research, porous scaffolds made of polycaprolactone (PCL) and nano-hydroxyapatite (nHA) were used as cell carriers. Then, the scaffolds loaded with bone marrow mesenchymal stem cells (BMSCs) were treated with sinusoidal electromagnetic field and the osteogenic capability of BMSCs was tested later. In addition, an intervertebral disc of the tail vertebra of the rat was removed to construct a spinal intervertebral fusion model with a cell-scaffold implanted. The intervertebral fusion was observed and analyzed by X-ray, micro-CT, and histological methods.
BMSCs stimulated by EMF possess splendid osteogenic capability under an osteogenic medium (OM) in vitro. And the conditioned medium of BMSCs treated with EMF can further promote osteogenic differentiation of the primitive BMSCs. Mechanistically, EMF regulates BMSCs via BMP/Smad and mitogen-activated protein kinase (MAPK)-associated p38 signaling pathways. In vivo experiments revealed that the scaffold loaded with BMSCs stimulated by EMF accelerated intervertebral fusion successfully.
In summary, EMF accelerated intervertebral fusion by improving the osteogenic capacity of BMSCs seeded on scaffolds and might boost the paracrine function of BMSCs to promote osteogenic differentiation of the homing BMSCs at the injured site. EMF combined with tissue engineering techniques may become a new clinical treatment for LDD.
脊柱融合术是治疗腰椎退行性疾病（LDD）最常见的手术。手术中使用的移植物材料取自髂嵴以促进融合。然而，自体移植物存在来源不足的致命缺点。因此，迫切需要开发经济实用的骨替代物。正弦电磁场（EMF）与组织工程技术相结合可能是促进脊柱融合的一种合适方法。
在这项研究中，聚己内酯（PCL）和纳米羟基磷灰石（nHA）制成的多孔支架被用作细胞载体。然后，将负载骨髓间充质干细胞（BMSCs）的支架用正弦电磁场处理，然后测试 BMSCs 的成骨能力。此外，切除大鼠尾椎的椎间盘，植入细胞-支架构建脊柱椎间盘融合模型。通过 X 射线、微 CT 和组织学方法观察和分析脊柱融合。
体外成骨培养基（OM）中 EMF 刺激的 BMSCs 具有出色的成骨能力。并且 EMF 处理的 BMSCs 的条件培养基可以进一步促进原始 BMSCs 的成骨分化。从机制上讲，EMF 通过 BMP/Smad 和丝裂原活化蛋白激酶（MAPK）相关 p38 信号通路调节 BMSCs。体内实验表明，负载 EMF 刺激的 BMSCs 的支架成功加速了脊柱融合。
总之，EMF 通过提高支架上接种的 BMSCs 的成骨能力加速了脊柱融合，并可能增强 BMSCs 的旁分泌功能，促进损伤部位归巢 BMSCs 的成骨分化。EMF 与组织工程技术相结合可能成为治疗 LDD 的新临床治疗方法。
