Xu Chao, Wang Shuang, Liu Langlang, Yu Suchun, Wu Xiaopei, Dai Honglian
J Biomed Nanotechnol. 2019 Feb 1;15(2):301-310. doi: 10.1166/jbn.2019.2683.
In this study, hollow mesoporous ferrite nanoparticles (HMFNs) were prepared. It showed a spherical morphology with a diameter about 320 nm, with a negatively charged surface, and with a great superparamagnetic property. Negative charge attribute to the free -OH group of the HMFNs shell, which improved nanoparticles hydrophilic and biocompatibility. Superparamagnetic property could avoids particle agglomeration. The particles were shown to be internalized into the bone marrow mesenchymal stem cells (BMSCs) . We found that the intracellular HMFNs can improve the osteogenic differentiation of BMSCs in the presence of an electromagnetic fields. To determine the optimal intensity of the sinusoidal electromagnetic field (SEMF), the exposure levels of 50 Hz SEMF in the range of 0∼4 mTs (60 min/day) were utilized to investigate its effects on the proliferation and osteogenic differentiation of rat BMSCs. The result showed that the 1 mT and 2 mT SEMF stimulated the BMSCs proliferation significantly. The internalized HMFNs in conjunction with SEMF exposure enhanced the osteogenic differentiation, as evidenced by elevated alkaline phosphatase activity, calcium deposition, and the expression protein levels of the expression profile of osteopontin, osteocalcin and runt-related transcription factor 2. We believe that the electromagnetic fields can manipulate osteogenic differentiation of BMSCs using intracellular superparamagnetic nanoparticles.
在本研究中，制备了中空介孔铁氧体纳米颗粒（HMFNs）。其呈现出直径约为320 nm的球形形态，表面带负电荷，具有很强的超顺磁性。负电荷归因于HMFNs壳层的游离 -OH基团，这提高了纳米颗粒的亲水性和生物相容性。超顺磁性可避免颗粒团聚。这些颗粒被证明可内化进入骨髓间充质干细胞（BMSCs）。我们发现，在存在电磁场的情况下，细胞内的HMFNs可促进BMSCs的成骨分化。为了确定正弦电磁场（SEMF）的最佳强度，利用0∼4 mT（每天60分钟）范围内的50 Hz SEMF暴露水平来研究其对大鼠BMSCs增殖和成骨分化的影响。结果表明，1 mT和2 mT的SEMF显著刺激了BMSCs的增殖。内化的HMFNs与SEMF暴露相结合增强了成骨分化，碱性磷酸酶活性升高、钙沉积以及骨桥蛋白、骨钙素和 runt相关转录因子2表达谱的表达蛋白水平升高证明了这一点。我们认为，电磁场可利用细胞内超顺磁性纳米颗粒来调控BMSCs的成骨分化。
