Influence of thickness on the properties of electrospun PCL/gelatin nanofiber scaffolds

Electrospun nanofiber scaffolds mimic the structure of the natural extracellular matrix, making them promising for application in tissue engineering. Based on this, the biopolymers poly(ε-caprolactone) (PCL) and gelatin, with good mechanical and biological properties, respectively, were electrospun with acetic acid as the only solvent, without the crosslinking process in order to reduce the cytotoxic effects of commonly used solvents. This study evaluated the influence of scaffold thicknesses on the physicochemical properties. Scaffolds with 4 different thicknesses were produced by increasing the electrospinning time (A = 1 h, B = 1.5 h, C = 2 h and D = 3 h). Thicker scaffolds (B, C and D, 0.142 ± 0.029 to 0.306 ± 0.053 nm) were manipulated easily, presented higher mechanical strength (from 156.21 to 178.53%) and smaller diameter fibers (approximately 300.0 nm). On the other hand, the longer the processing time, the less uniform the fibers and more melting regions between fibers, which may hinder the use of the scaffold and should be considered. Only the thickest scaffold (D) showed higher wettability (contact angle 31.1° ± 3°). Intermediate thickness scaffolds showed less beads and fiber irregularities. Cell adhesion was good due to gelatin, though cell proliferation remained constant for the thicker scaffold indicating that longer processing time may not be advantageous for cell application. Results showed that intermediate thickness scaffolds of PCL/gelatin (0.142 ± 0.029 to 0.195 ± 0.034 nm) assure good physicochemical properties to be applied for different cell types.