Evaluation of electrospinning parameters on the tensile strength and suture retention strength of polycaprolactone nanofibrous scaffolds through surface response methodology

Scaffolds should provide sufficient biomechanical support during tissue regeneration for tissue engineering (TE) applications. Electrospun scaffolds are commonly applied in TE applications due to their tunable physical, chemical, and mechanical properties as well as their similarity to extracellular matrix. Although the mechanical properties of electrospun scaffolds are highly dependent on processing parameters, a limited number of studies have systematically investigated this subject. The present study has investigated the effects of the main electrospinning parameters on tensile and suture retention strength of polycaprolactone (PCL) scaffolds using response surface methodology. Scaffolds morphology and cell-scaffold interaction were also investigated in this study. According to the fitted model, polymer concentration and feed rate have the most significant positive effect on both the tensile and suture retention strength. Whereas applied voltage negatively affected both the tensile and suture retention strength. The effect of distance on tensile strength was not significant while its effect on suture retention was different depending on its values. Changes in biomechanical properties were associated with gross alterations in morphology of the fibers and cell-scaffold interaction. Scaffolds with lowest tensile strength presented a beaded morphology while scaffolds with higher tensile strength presented beadless morphology with worm-like fibers. The increase in tensile strength was correlated with the increase in average diameter of the fibers and pore size. The results of cell culture study showed that fibroblasts stretched and proliferated more on scaffolds with lower tensile strength. The generated model might be helpful when PCL scaffold with desirable tensile and suture retention strength are required. Furthermore, the results suggest that changes in morphology and subsequent cell-scaffold interaction should be considered when these biomechanical properties are optimized.