Yu Fei, Cheng Shaoyu, Lei Jiehua, Hang Yingjie, Liu Qi, Wang Hongwei, Yuan Lin
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, People's Republic of China.
J Biomater Sci Polym Ed. 2020 Sep;31(13):1623-1647. doi: 10.1080/09205063.2020.1767375. Epub 2020 May 27.
The replacement therapy or transplantation using neural cells, which differentiated from stem cells, has emerged as a promising strategy for repairing damaged neural tissues and helping functional recovery in the treatment of neural system diseases. The challenge, however, is how to control embryonic stem cell fate so that neural differentiation can be efficiently directed to enrich a neuron cell population, and meanwhile to maintain their bioactivities. This is a key question and has a very significant impact in regenerative medicine. Here we proposed a new neural-differentiation inductive nanocomposite, containing gold nanoparticles (AuNPs), poly(2-methacrylamido glucopyranose--3-sulfopropyl acrylate) (PMS), and basic fibroblast growth factor (FGF2), for the high efficient directional neural-specific differentiation of mouse embryonic stem cells (mESCs). In this AuNP-PMS/FGF2 composite, PMS, playing as the high-active mimic of heparin/heparan sulfate (HS), is covalently anchored to AuNPs and bound with FGF2 on the surface of nanoparticles, forming a HS/FGF2 complex nanomimics to facilitate its binding to FGF receptor (FGFR) and promote high neural-inductive activity of mESCs. The stability, bioactivity and biocompatibility of the composite are investigated in this study. The results showed that the AuNP-PMS/FGF2 composite could maintain a long-term stability at room temperature for at least 8 days, and greatly promote the neural differentiation of mESCs. Compared with the other materials, the AuNP-PMS/FGF2 composite could significantly stimulate the expression of the specific neural differentiation markers (nestin and β3-tubulin), while obviously down-regulate the mRNA production of pluripotency marker Oct-4 in mESCs. Moreover, the promotion effect of the composite on neuronal maturation marker β3-tubulin expression achieved maximally at the low concentration of FGF2 (4 ng/mL), which suggested the high efficiency of AuNP-PMS/FGF2 composite in neural differentiation of mESCs. Meanwhile, both mESCs and L929 cells showed desirable growth during the incubation with AuNP-PMS/FGF2 composite. The AuNP-PMS/FGF2 system presents a new way to achieve HS/FGF2 complex nanomimics efficiently for the neural differentiation of mESCs.
利用从干细胞分化而来的神经细胞进行替代疗法或移植，已成为修复受损神经组织和促进神经系统疾病治疗中功能恢复的一种有前景的策略。然而，挑战在于如何控制胚胎干细胞的命运，以便有效地引导神经分化以富集神经元细胞群体，同时保持其生物活性。这是一个关键问题，对再生医学有非常重大的影响。在此，我们提出了一种新的神经分化诱导纳米复合材料，其包含金纳米颗粒（AuNPs）、聚（2-甲基丙烯酰胺基吡喃葡萄糖-3-磺酸丙酯丙烯酸酯）（PMS）和碱性成纤维细胞生长因子（FGF2），用于小鼠胚胎干细胞（mESCs）的高效定向神经特异性分化。在这种AuNP-PMS/FGF2复合材料中，PMS作为肝素/硫酸乙酰肝素（HS）的高活性模拟物，共价锚定在AuNPs上并与纳米颗粒表面的FGF2结合，形成HS/FGF2复合纳米模拟物，以促进其与FGF受体（FGFR）的结合并促进mESCs的高神经诱导活性。本研究对该复合材料的稳定性、生物活性和生物相容性进行了研究。结果表明，AuNP-PMS/FGF2复合材料在室温下可保持至少8天的长期稳定性，并极大地促进了mESCs的神经分化。与其他材料相比，AuNP-PMS/FGF2复合材料可显著刺激特定神经分化标志物（巢蛋白和β3-微管蛋白）的表达，同时明显下调mESCs中多能性标志物Oct-4的mRNA产生。此外，该复合材料对神经元成熟标志物β3-微管蛋白表达的促进作用在低浓度FGF2（4 ng/mL）时达到最大，这表明AuNP-PMS/FGF2复合材料在mESCs神经分化中具有高效性。同时，在与AuNP-PMS/FGF2复合材料孵育期间，mESCs和L929细胞均显示出良好的生长。AuNP-PMS/FGF2系统为有效实现HS/FGF2复合纳米模拟物用于mESCs的神经分化提供了一种新方法。
