Zeitschrift für Materialwissenschaften und Ingenieurwesen

Electrospun Polyglycolic Acid-Poly(Carbonate-Urea) Urethane Scaffold as a Hybrid Tissue Engineered Vessel

Abstract

Clay Quint

Alternative small diameter vascular grafts are needed for patients that require surgical revascularization in patients lacking autologous vein. In this study, a Polyglycolic Acid (PGA)-Thermoplastic Polyurethane (TPU) electrospun scaffold seeded with human dermal fibroblasts was placed in a biomimetic perfusion system to generate a hybrid tissue engineered vessel. The outer layer was an electrospun PGA that was co-electrosprayed with sacrificial polyethylene oxide (PEO) microparticles to increase porosity. The PGA-TPU scaffold remained static for 1 week, then circumferential strain amplitude was incremented from 1% to 5% over 6 weeks. The hybrid tissue engineered vessel had an outer cellular layer with collagen deposition replacing the biodegradable PGA and the inner residual polyurethane layer remained relatively acellular. The tensile properties of the hybrid tissue engineered vessel demonstrated a significant reduction in the elastic modulus compared to the PGA-TPU scaffold, but the ultimate tensile strength, extension to break, and burst pressure remained stable. Fouriertransform infrared spectroscopy confirmed the degradation of the PGA and a reduction of polyurethane crosslinking in the hybrid TEV compared to the PGA-TPU. Thus, a biomimetic perfusion system can be used to evaluate the biocompatibility of an electrospun polyurethane scaffold in vitro, to understand the mechanical changes of the polyurethane scaffold after exposure to circumferential stretch, and to generate a hybrid tissue engineered vessel with suitable characteristics for implantation.