From self-assembly of electrospun nanofibers to 3D cm thick hierarchical foams

Electrospinning usually results in the formation of scaffolds that are a few hundred microns in thickness with pore sizes in the micron range. However some applications, such as tissue engineering, necessitate the fabrication of cm-thick nanofibrous scaffolds with large pore sizes that allow for cell infiltration. Here, we demonstrate for the first time the production of bioresorbable poly(ε-caprolactone) nanofibrous cm-thick foams using the electrospinning technique. These scaffolds were obtained through the dynamic self-assembly of electrospun nanofibers into honeycomb patterns, which resulted in a unique columnar hierarchical structure with both micropores and mesopores of up to several hundreds of microns in size. This specific morphology leads to mechanical properties of thick scaffolds, suitable for handling and implanting in vivo.