De novo reconstitution of a functional mammalian urinary bladder by tissue engineering

Abstract
Human organ replacement is limited by a donor shortage, problems with tissue compatibility, and rejection. Creation of an organ with autologous tissue would be advantageous. In this study, transplantable urinary bladder neo–organs were reproducibly created in vitro from urothelial and smooth muscle cells grown in culture from canine native bladder biopsies and seeded onto preformed bladder–shaped polymers. The native bladders were subsequently excised from canine donors and replaced with the tissue–engineered neo–organs. In functional evaluations for up to 11 months, the bladder neo–organs demonstrated a normal capacity to retain urine, normal elastic properties, and histologic architecture. This study demonstrates, for the first time, that successful reconstitution of an autonomous hollow organ is possible using tissue–engineering methods.