Development of Tissue Engineered Heart Valves for Percutaneous Transcatheter Delivery in a Fetal Ovine Model

[Display omitted] •A fully biodegradable fetal valve was developed using a zinc-aluminum alloy stent and electrospun PCL leaflets.•In vitro evaluation of the valve was performed with accelerated degradation, mechanical, and flow loop testing, and the valve showed trivial stenosis and trivial regurgitation.•A large animal model was used for percutaneous delivery of the valve to the fetal pulmonary annulus.•Following implantation, the valve had no stenosis or regurgitation by echocardiography, and the fetal sheep matured and was delivered at term with the tissue-engineered valve. This multidisciplinary work shows the feasibility of replacing the fetal pulmonary valve with a percutaneous, transcatheter, fully biodegradable tissue-engineered heart valve (TEHV), which was studied in vitro through accelerated degradation, mechanical, and hemodynamic testing and in vivo by implantation into a fetal lamb. The TEHV exhibited only trivial stenosis and regurgitation in vitro and no stenosis in vivo by echocardiogram. Following implantation, the fetus matured and was delivered at term. Replacing a stenotic fetal valve with a functional TEHV has the potential to interrupt the development of single-ventricle heart disease by restoring proper flow through the heart.