Tailoring Electrospinning Fabrication for Scaffolds for Heart Valve Tissue Engineering

Previous work in controlling mechanical properties of electrospun scaffolds has largely been limited to altering the orientation of the fibrous network by either large rotational velocity or by altering the electric field during fabrication. Our lab has previously developed a technique to analyze the complete microstructural topology of electrospun scaffolds and extract key descriptors. In this project, we translated the target mandrel at varying speeds along its rotational axis in order to modify the microarchitecture without altering the fiber orientation angle. Using the algorithm mentioned above, we determined that increasing the translation speed resulted in a decrease in fiber intersections/µm2. Relating this measure to mechanical response, it appeared that higher fiber intersection densities were correlated with higher strain energies, and higher mechanical anisotropy (p<.001). Additionally, we demonstrate that concurrently electrospraying cell culture media during fabrication appears to amplify the effect of rastering on the scaffold mechanics. These results suggest that fiber orientation is not sufficient to describe the mechanical response of electrospun scaffolds. It is also demonstrated that soft tissue like anisotropy can be induced in electrospun scaffolds at low mandrel tangential velocity by the reduction of the translation velocity and the concurrent electrospraying of cell culture media, greatly facilitating ease of fabrication.