A polyurethane-gelatin hybrid construct for manufacturing implantable bioartificial livers

A novel 3D hybrid construct was developed for liver manufacturing by depositing biodegradable polyurethane (PU) and a naturally derived polymer gelatin simultaneously via a double nozzle rapid prototyping (RP) technique. A grid object was produced by precisely and simultaneously dispersing the PU and gelatin to form 3D constructs with interconnected macro-channels at a low temperature (-28 degrees C). Micro-pores were formed by freeze-drying the constructs. The PU polymer provided mechanical support while gelatin provided accommodation for implant cells. The hydrophilicity of the hybrid constructs was between the pure PU and pure gelatin structures. The interconnected channels allow nutrients and oxygen to be supplied throughout the construct as well as provide space for the attachment of cells. The design and fabrication strategies, used to create complex physical objects directly from computer aided design (CAD) models, represent a promising technique for implantable bioartificial livers. It is anticipated that these PU-gelatin hybrid constructs will serve as a useful model for bioartificial liver manufacturing.