Liu Zhongyang, Huang Liangliang, Liu Liang, Luo Beier, Liang Miaomiao, Sun Zhen, Zhu Shu, Quan Xin, Yang Yafeng, Ma Teng, Huang Jinghui, Luo Zhuojing
Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China.
Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Int J Nanomedicine. 2014 Dec 17;10:43-61. doi: 10.2147/IJN.S74332. eCollection 2015.
Schwann cells (SCs) are attractive seed cells in neural tissue engineering, but their application is limited by attenuated biological activities and impaired functions with aging. Therefore, it is important to explore an approach to enhance the viability and biological properties of SCs. In the present study, a magnetic composite made of magnetically responsive magnetic nanoparticles (MNPs) and a biodegradable chitosan-glycerophosphate polymer were prepared and characterized. It was further explored whether such magnetic nanocomposites via applied magnetic fields would regulate SC biological activities. The magnetization of the magnetic nanocomposite was measured by a vibrating sample magnetometer. The compositional characterization of the magnetic nanocomposite was examined by Fourier-transform infrared and X-ray diffraction. The tolerance of SCs to the magnetic fields was tested by flow-cytometry assay. The proliferation of cells was examined by a 5-ethynyl-2-deoxyuridine-labeling assay, a PrestoBlue assay, and a Live/Dead assay. Messenger ribonucleic acid of BDNF, GDNF, NT-3, and VEGF in SCs was assayed by quantitative real-time polymerase chain reaction. The amount of BDNF, GDNF, NT-3, and VEGF secreted from SCs was determined by enzyme-linked immunosorbent assay. It was found that magnetic nanocomposites containing 10% MNPs showed a cross-section diameter of 32.33±1.81 µm, porosity of 80.41%±0.72%, and magnetization of 5.691 emu/g at 8 kOe. The 10% MNP magnetic nanocomposites were able to support cell adhesion and spreading and further promote proliferation of SCs under magnetic field exposure. Interestingly, a magnetic field applied through the 10% MNP magnetic scaffold significantly increased the gene expression and protein secretion of BDNF, GDNF, NT-3, and VEGF. This work is the first stage in our understanding of how to precisely regulate the viability and biological properties of SCs in tissue-engineering grafts, which combined with additional molecular factors may lead to the development of new nerve grafts.
施万细胞（SCs）是神经组织工程中颇具吸引力的种子细胞，但其应用受到衰老导致的生物活性减弱和功能受损的限制。因此，探索一种增强施万细胞活力和生物学特性的方法具有重要意义。在本研究中，制备并表征了一种由磁响应磁性纳米颗粒（MNPs）和可生物降解的壳聚糖 - 甘油磷酸聚合物制成的磁性复合材料。进一步探究了这种磁性纳米复合材料在施加磁场的情况下是否会调节施万细胞的生物学活性。通过振动样品磁强计测量磁性纳米复合材料的磁化强度。通过傅里叶变换红外光谱和X射线衍射对磁性纳米复合材料进行成分表征。通过流式细胞术检测施万细胞对磁场的耐受性。通过5 - 乙炔基 - 2 - 脱氧尿苷标记试验、PrestoBlue试验和活/死试验检测细胞增殖情况。通过定量实时聚合酶链反应检测施万细胞中脑源性神经营养因子（BDNF）、胶质细胞源性神经营养因子（GDNF）、神经营养因子 - 3（NT - 3）和血管内皮生长因子（VEGF）的信使核糖核酸。通过酶联免疫吸附测定法测定施万细胞分泌的BDNF﹑GDNF﹑NT - 3和VEGF的量。结果发现，含有10% MNPs的磁性纳米复合材料的横截面直径为32.33±1.81 µm，孔隙率为80.41%±0.72%，在8 kOe下的磁化强度为5.691 emu/g。10% MNP磁性纳米复合材料能够支持细胞黏附和铺展，并在磁场暴露下进一步促进施万细胞的增殖。有趣的是，通过10% MNP磁性支架施加的磁场显著增加了BDNF、GDNF、NT - 3和VEGF的基因表达和蛋白质分泌。这项工作是我们理解如何精确调节组织工程移植物中施万细胞活力和生物学特性的第一阶段，与其他分子因素相结合可能会促成新型神经移植物的开发。
