Expansion of two-dimension electrospun nanofiber mats into threedimension scaffolds

Electrospinning has been the preferred technology in producing a synthetic, functional scaffold due to the biomimicry to extracellular matrix and the ease control of composition, structure, and diameter of fibers. However, despite these advantages, traditional electrospun nanofiber scaffolds come with limitations including disorganized nanofiber orientation, low porosity, small pore size, and mainly two-dimensional mats. As such, there is a great need for developing a new process for fabricating electrospun nanofiber scaffolds that can overcome the above limitations. Herein, a novel and simple method is outlined. A traditional 2D nanofiber mat is transformed into a 3D scaffold with desired thickness, gap distance, porosity, and nanotopographic cues to allow for cell seeding and proliferation through the depressurization of subcritical CO ₂ fluid. In addition to providing a scaffold for tissue regeneration to occur, this method also provides the opportunity to encapsulate bioactive molecules such as antimicrobial peptides for local drug delivery. The CO ₂ expanded nanofiber scaffolds hold great potential in tissue regeneration, wound healing, 3D tissue modeling, and topical drug delivery.