Leveraging physical factors in cellular microenvironments to promote adipose tissue-derived stem cell (ADSC) osteogenic differentiation has emerged as a new strategy in the development of scaffolds for bone tissue engineering. Anisotropicity is one of those factors of interest; however, the utilization of anisotropicity to promote ADSC osteogenic differentiation is still not efficient. In this study, we designed a substrate with a dual anisotropic structure fabricated via a combination of 3D printing and magnetic field-induced magnetic nanoparticle assembly techniques. These dual anisotropic structures have a scale hierarchy, and the scale of the magnetic nanoparticle assemblies matches that of a single ADSC. This is in contrast to conventional anisotropic osteogenic induction scaffolds that have anisotropic structures at only one scale and at an order of magnitude different from single ADSCs. ADSCs cultured on substrates with such structures have significantly higher osteogenic marker expression, e.g., ALP, at both the protein and mRNA levels, and more calcium nodule formation was also found, suggesting a stronger tendency toward osteogenic differentiation of ADSCs. RNA-seq data revealed that alterations in kinase signaling pathway transduction, cell adhesion, and cytoskeletal reconstruction may account for the elevated osteogenic induction capacity. These data support our hypothesis that such a structure could maximize the anisotropicity that ADSCs can sense and therefore promote ADSC osteogenic differentiation.

利用细胞微环境中的物理因素来促进脂肪组织衍生的干细胞（ADSC）的成骨分化已成为开发骨组织工程支架的一种新策略。各向异性是这些感兴趣的因素之一；然而，利用各向异性来促进ADSC成骨分化仍然不是有效的。在这项研究中，我们设计了一种具有双重各向异性结构的基板，该基板是通过3D打印和磁场感应的磁性纳米粒子组装技术相结合而制成的。这些双重各向异性结构具有尺度层次，磁性纳米粒子组件的尺度与单个ADSC的尺度相匹配。这与常规各向异性的成骨诱导支架相反，常规的各向异性成骨诱导支架仅在一个尺度上具有与单个ADSC不同的数量级的各向异性结构。在具有这种结构的底物上培养的ADSC在蛋白质和mRNA水平上均具有显着更高的成骨标志物表达，例如ALP，并且还发现了更多的钙结节形成，表明ADSC趋向成骨分化的趋势更强。RNA-seq数据显示，激酶信号传导途径的转导，细胞粘附和细胞骨架重建的改变可能是导致成骨诱导能力增强的原因。这些数据支持我们的假设，即这样的结构可以使ADSC可以感知的各向异性最大化，从而促进ADSC成骨分化。