State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200438, China.
Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai 200434, China.
ACS Appl Mater Interfaces. 2022 Aug 24;14(33):37436-37446. doi: 10.1021/acsami.2c10006. Epub 2022 Aug 9.
Directed migration of cells through cell-surface interactions is a paramount prerequisite in biomaterial-induced tissue regeneration. However, whether and how the nanoscale spatial gradient of adhesion molecules on a material surface can induce directed migration of cells is not sufficiently known. Herein, we employed block copolymer micelle nanolithography to prepare gold nanoarrays with a nanospacing gradient, which were prepared by continuously changing the dipping velocity. Then, a self-assembly monolayer technique was applied to graft arginine-glycine-aspartate (RGD) peptides on the nanodots and poly(ethylene glycol) (PEG) on the glass background. Since RGD can trigger specific cell adhesion via conjugating with integrin (its receptor in the cell membrane) and PEG can resist protein adsorption and nonspecific cell adhesion, a nanopattern with cell-adhesion contrast and a gradient of RGD nanospacing was eventually prepared. In vitro cell behaviors were examined using endothelial cells (ECs) and smooth muscle cells (SMCs) as a demonstration. We found that SMCs exhibited significant orientation and directed migration along the nanospacing gradient, while ECs exhibited only a weak spontaneously anisotropic migration. The gradient response was also dependent upon the RGD nanospacing ranges, namely, the start and end nanospacings under a given distance and gradient. The different responses of these two cell types to the RGD nanospacing gradient provide new insights for designing cell-selective nanomaterials potentially used in cell screening, wound healing, etc.
细胞通过细胞表面相互作用的定向迁移是生物材料诱导组织再生的首要前提。然而，材料表面黏附分子的纳米级空间梯度是否以及如何诱导细胞的定向迁移还不完全清楚。在此，我们采用嵌段共聚物胶束纳米光刻技术，通过连续改变浸渍速度来制备具有纳米间距梯度的金纳米阵列。然后，采用自组装单层技术将精氨酸-甘氨酸-天冬氨酸（RGD）肽接枝到纳米点上，将聚乙二醇（PEG）接枝到玻璃基底上。由于 RGD 可以通过与整合素（细胞膜中的受体）结合触发特定的细胞黏附，而 PEG 可以抵抗蛋白质吸附和非特异性细胞黏附，因此最终制备出具有细胞黏附对比度和 RGD 纳米间距梯度的纳米图案。我们以血管内皮细胞（ECs）和血管平滑肌细胞（SMCs）为例，研究了体外细胞行为。结果发现，SMC 沿着纳米间距梯度表现出显著的取向和定向迁移，而 EC 仅表现出较弱的自发各向异性迁移。梯度响应还取决于 RGD 纳米间距范围，即在给定距离和梯度下的起始和结束纳米间距。这两种细胞类型对 RGD 纳米间距梯度的不同反应为设计用于细胞筛选、伤口愈合等的细胞选择性纳米材料提供了新的见解。
