Portable nanofiber meshes dictate cell orientation throughout three-dimensional hydrogels

In this study, a new technique that controls individual cell orientation using nanofiber meshes within three-dimensional (3D) hydrogels is reported. Highly aligned and fragile electrospun nanofibers (average diameter 500 nm) were manufactured into portable and handleable meshes with average line density of 45 nanofibers per 100 mu m and thickness ranging between 0.5 and 3.0 mu m. Through a facile and reproducible fabrication process, the nanofiber meshes can be incorporated into 3D hydrogels via a bottom-up, layer-by-layer assembly process, resulting in macroscopic and highly organized scaffolds. The nanofibers dictated the orientation of the cytoskeleton of individual cells in a very precise manner, allowing altering of the orientation of a cell population throughout the thickness of the hydrogel. Addition of nanofibers affected cell phenotype and protein synthesis. This nanofiber-cell-hydrogel composite enables replication of the cellular and matrix architecture found in many natural tissues, offering a novel protocol for electrospun nanofibers in regenerative medicine and bioengineering. From the Clinical Editor: A novel protocol for highly organized nanofiber meshes incorporated into 3D hydrogels can be used to direct the overlying cell population cytoskeleton direction, phenotype, and protein synthesis. Nanospun matrices offers a significant advancement for controlled tissue bioengineering and regenerative medicine applications. (C) 2011 Elsevier Inc. All rights reserved.