Storage stability of electrospun pure gelatin stabilized with EDC/Sulfo-NHS

With the rapid development of biomimetic polymers for cell-based assays and tissue engineering, crosslinking electrospun nanofibrous biopolymer constructs is of great importance for achieving sustainable and efficient three-dimensional scaffold constructs. Uncrosslinked electrospun gelatin nanofibrous constructs immediately and completely dissolved in aqueous solutions due to their aqueous solubility and poor storage stability. Here, a novel and versatile approach for the fabrication and crosslinking of electrospun gelatin construct with tunable porosity and high aspect ratio nanofibers is presented. Uncrosslinked electrospun gelatin/genipin nanofibrous and pure gelatin nanofibrous constructs exhibited smooth surfaces that were well-defined, with a diameter in the range of 448 ± 364 nm and 257 ± 57 nm, respectively. Dehydrothermal, genipin-EDC/Sulfo-NHS, and EDC/Sulfo-NHS crosslinking approaches were examined to achieve insoluble gelatin nanofibrous constructs that were suitable for cell-based assays. Mechanical characterization demonstrated that the pure gelatin nanofibrous construct crosslinked via EDC/Sulfo-NHS exhibited an increased mechanical strength and stiffness and showed no dissolution in aqueous solutions and retained its fiber morphology. An excellent 1 month storage stability was demonstrated at 22, 4, -20, and -80°C (dehydrated) and at 4°C (hydrated). The as-crosslinked gelatin nanofibrous construct was highly biocompatible (90% cell viability), as demonstrated by the promoted proliferation of PC12 cells.