Optimization of Polyurethane Scaffolds by Taguchi Design of Experiments for Vascular Tissue Engineering Applications

Vascular tissue engineering offers innovative solutions to the vascular replacement problems, especially low diameter grafts. Electrospinning is a cost-effective and versatile method for producing tissue engineering scaffolds. Although this method is relatively simple, but at theoretical level the interactions between process parameters and their influence on fiber morphology are not yet fully understood. In this paper, the aim was to find the optimal electrospinning parameters to obtain the smallest fiber diameter by Taguchi’s methodology for vascular tissue engineering applications.

The scaffolds were produced by electrospinning of a polyurethane solution in dimethylformamide. Polymer concentration and process parameters were considered as effective factors. Taguchi’s L9 orthogonal design was applied to the experiential design. Optimal conditions were determined using the signal-to-noise (S/N) ratio with Minitab 17 software. The morphology of the nanofibers was studied by an SEM. Then, human umbilical vein endothelial cells (HUVECs) were cultured on the optimal scaffolds to investigate cellular toxicity of the scaffolds and cell adhesion.

The analysis of experiments showed that polyurethane concentration was the most significant parameter. An optimum combination to reach the smallest diameters was obtained at 12 wt% polymer concentration, 16 kV of the supply voltage, 0.1 mL/h feed rate and 15 cm tip-to-distance. The average diameter of the nanofibers was predicted in the range of 242.10 to 257.92 nm at a confidence level of 95%. The optimum diameter of the nanofibers was experimentally 258±30 nm, which is in good agreement with the estimated value of the Taguchi’s methodology. Cell viability was also reported to be 88.59% and the cells showed good adhesion to the scaffold. These scaffolds can show promising results in mimicking the extracellular matrix and thus in vascular tissue engineering.