Tissue Engineering Cardiovascular Grafts with Direct Current and Alternating Field Electrospinning.*

As cardiovascular diseases (CVD) are a leading cause of death, this study proposes a platform for coronary artery bypass grafts from a main polymer of fish skin gelatin (FGel) electrospun into nanofibrous (NF) material. This FGel NF material was electrospun by a complex electrohydrodynamic process of Direct Current electrospinning (DCES), currently utilized in industry, and novel Alternating Field electrospinning (AFES). Both DCES and AFES complement each other with AFES having advantages. DCES has limitation of low throughput, while AFES achieved markedly higher productivity of 36ml/h to DCES 0.8ml/h without sacrificing the Extracellular Matrix (ECM) NF quality. The ECM were fabricated from a biocompatible polymer of FGel. FGel precursors 35–50wt% were selected for long fibers, minimal beading, and yield. Scanning electron Microscopy confirmed both DCES and AFES production of an ECM. As-spun ECM were thermally crosslinked (TX) at 160°C for 8h to improve the NF's mechanical strength. The TX FGel 50wt% ECM had a NF diameter of 404±110nm while DCES had NF diameters an order of magnitude smaller leaving both NF diameters in the ECM's optimal range of 50–500nm. Dynamic Mechanical Analysis on the AFES TX scaffolds evaluated elastic/viscoelastic properties under increasing frequency at room temperature. The FGel ECM tolerated up to 2Hz before permanent deformation. These findings highlight the potential of FGel NF scaffolds as cardiovascular grafts for CVD utilizing two different fabrication techniques.