ABSTRACT:The field of regenerative medicine continues to make substantial advancements in therapeutic strategies addressing urologic diseases. Tissue engineering borrows principles from the fields of cell biology, materials science, transplantation and engineering in an effort to repair or replace damaged tissues. This review is intended to provide a current overview of the use of stem cells and tissue engineering technologies specifically in the treatment of genitourinary diseases. Current themes in the field include the use of adult stem cells seeded onto biocompatible resorbable matrices for implantation as tissue substitutes, which is conducive to host tissue ingrowth. Injection therapy of adult stem cells for organ rehabilitation is also making strong headway toward the restoration of organ structure and function. With new data describing the molecular mechanisms for differentiation, work has begun on targeting tissues for regeneration by genetic modification methods. Promising laboratory discoveries portend the emergence of a new class of clinical therapies for regenerative medicine applications in the genitourinary tract. T he field of tissue engineering (TE) has evolved substantially over the past four decades into an international area of science that is being investigated in virtually every country in the world. Early advances in the field were the result of groundbreaking discoveries of the pioneers in the regenerative medicine field including Joseph and Charles Vacanti, Robert Langer, and Eugene Bell. In fact, it was Joseph and Charles Vacanti who first used the term "Tissue Engineering" (1). They eloquently described the interplay required by cells, scaffolds, and added growth factors in the microenvironment of mechanotransducing bioreactors to develop cellular constructs that could ultimately serve as functional tissues suitable for transplantation. The field of TE has exponentially grown in size such that it now claims its own international academic society, Tissue Engineering Regenerative Medicine International Society, which the expanding community of scientists and physicians in the field have steadfastly supported (1-4). As of today, the principles of TE are being applied widely to create new tissue constructs in virtually every organ system.In general, the field of TE combines the principles of cell biology, materials science, and engineering to devise therapeutic strategies in various acquired and congenital diseases (5-7). From a clinical perspective, the goal of regenerative medicine efforts is to restore end organ function, either by native tissue rehabilitation, or by development of functional reproducible tissue substitutes with minimal immunogenicity and which resemble native tissues in biologic and mechanical properties.When autologous tissue is lacking, other possible sources of tissue include homologous tissues from cadavers or donors, heterologous tissues from animals (bovine), and synthetic materials (silicone, polyurethane, Teflon, poly(lactic acid), poly(glycolic acid), and poly...