Three-Dimensional Objects Consisting of Hierarchically Assembled Nanofibers with Controlled Alignments for Regenerative Medicine.

Assembling electrospun nanofibers with controlled alignment into three-dimensional (3D), complex, and predesigned shapes has proven to be a difficult task for regenerative medicine. Herein, we report a novel approach inspired by solids of revolution that transforms two-dimensional (2D) nanofiber mats of a controlled thickness into once-inaccessible 3D objects with predesigned shapes. The 3D objects are highly porous, consisting of layers of aligned nanofibers separated by gaps ranging from several micrometers to several millimeters. Upon compression, the objects are able to recover their original shapes. The porous objects can serve as scaffolds, guiding the organization of cells and producing highly ordered 3D tissue constructs. Additionally, subcutaneous implantation in rats demonstrates that the 3D objects enable rapid cell penetration, new blood vessel formation, and collagen matrix deposition. This new class of 3D hierarchical nanofiber architectures offers promising advancements in both in vitro engineering of complex 3D tissue constructs/models or organs and in vivo tissue repair and regeneration.