Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130, USA.
ACS Nano. 2009 May 26;3(5):1151-9. doi: 10.1021/nn900070z.
Electrospun nanofibers can be readily assembled into various types of scaffolds for applications in neural tissue engineering. The objective of this study is to examine and understand the unique patterns of neurite outgrowth from primary dorsal root ganglia (DRG) cultured on scaffolds of electrospun nanofibers having different orders, structures, and surface properties. We found that the neurites extended radially outward from the DRG main body without specific directionality when cultured on a nonwoven mat of randomly oriented nanofibers. In contrast, the neurites preferentially extended along the long axis of fiber when cultured on a parallel array of aligned nanofibers. When seeded at the border between regions of aligned and random nanofibers, the same DRG simultaneously expressed aligned and random neurite fields in response to the underlying nanofibers. When cultured on a double-layered scaffold where the nanofibers in each layer were aligned along a different direction, the neurites were found to be dependent on the fiber density in both layers. This biaxial pattern clearly demonstrates that neurite outgrowth can be influenced by nanofibers in different layers of a scaffold, rather than the topmost layer only. Taken together, these results will provide valuable information pertaining to the design of nanofiber scaffolds for neuroregenerative applications, as well as the effects of topology on neurite outgrowth, growth cone guidance, and axonal regeneration.
静电纺纳米纤维可以很容易地组装成各种类型的支架，用于神经组织工程。本研究的目的是研究和理解在具有不同阶数、结构和表面性质的静电纺纳米纤维支架上培养的原代背根神经节（DRG）的神经突生长的独特模式。我们发现，当在无规取向纳米纤维的无纺垫上培养时，神经突从 DRG 主体径向向外延伸，没有特定的方向性。相比之下，当在平行排列的取向纳米纤维上培养时，神经突优先沿纤维的长轴延伸。当接种在取向和无规纳米纤维区域的边界时，同一 DRG 同时在底层纳米纤维的响应下表达取向和无规神经突场。当在双层支架上培养时，其中每层中的纳米纤维沿不同方向取向，发现神经突依赖于两层中的纤维密度。这种双轴模式清楚地表明，神经突的生长可以受到支架中不同层的纳米纤维的影响，而不仅仅是最上层。总之，这些结果将为神经再生应用的纳米纤维支架设计以及拓扑结构对神经突生长、生长锥导向和轴突再生的影响提供有价值的信息。
