Electrospun 3D multi-scale fibrous scaffold for enhanced human dermal fibroblasts infiltration

Electrospun polymeric nanofibrous scaffold possesses significant potential in the field of tissue engineering due to its extracellular matrix mimicking topographical features that modulate a variety of key cellular activities. How-ever, traditional two-dimensional (2D) electrospun scaffolds are generally close-packed fiber mats which prohibit cell infiltration and proliferation. Consequently, the applications of electrospun scaffolds in regenerative medicine are li-mited. In this study, we detail the use of a needle collector to fabricate three-dimensional (3D) electrospun poly-e-cap-rolactone (PCL) scaffolds with multi-scale fiber dimensions. The resultant pore size is 4 times larger than conventional 2D electrospun scaffolds with interweaving micro (3.3 ± 0.6 μm) and nano (240 ± 50 nm) fibers. The scaffold was sur-face modified by grafting with gelatin molecules. It was found that surface modification significantly improved human dermal fibroblasts (HDFs) cell infiltration throughout the 3D multi-scale scaffold. Even after an extended culture period of up to 28 days, cell proliferation was well supported in the surface-modified 3D multi-scale scaffold as confirmed by Ki67 staining. Extracellular matrix proteins secreted by the HDFs was evident on the 3D multi-scale PCL scaffold showing promising potential to facilitate tissue regeneration, in particular dermal tissue engineering.