BIOARTIFICIAL ENDOCRINE ORGANS: AT THE CUTTING EDGE OF TRANSLATIONAL RESEARCH IN ENDOCRINOLOGY

Bioartificial endocrine organs are a recent promise of regenerative medicine, offering a translational perspective for the cure by transplantation of a number of endocrine and metabolic disorders. In 2007 we have designed with biocompatible material a 3D scaffold - bioreactor unit mimiking the 3D macro-microscopic geometry (here coined as “organomorphism”) of the human thyroid gland, choosen as a suitable model of endocrine soft tissue organ, with the intent of bioengineering directly “on the laboratory bench” (i.e. ex situ) a complete and functional bioartificial thyroid. This unit reproduces the architecture of the inner, human thyroid stromal / vascular scaffold (also called matrix), and replicates the original thyrocyte / vascular interface. It is now under intense investigation as an experimental tool to test cellular 3D auto-assembly of both heterologous and autologous thyroid tissue, and related vascular system, up to the ex situ generation of a 3D macroscopic thyroid gland. We believe that these studies will lay the groundwork for an innovative concept in regenerative medicine of endocrine organs, i.e. that the organomorphism of a biocompatible scaffold - bioreactor complex is essential to guide the 3D organization of seeded stem / precursor cells. Specifically, organomorphism may favour phenotypic differentiation of seeded cells towards glandular and vascular elements, eventually leading to a physiologically-competent and immunotolerant bioconstruct, macroscopically suitable for transplantation and clinical applications. We also envisage potential applications of this principle to the ex situ reconstruction of other endocrine glands, like the anterior pituitary and adrenals, and to complex soft tissue viscera including the thymus, and parts of the central nervous system.