Tissue Engineering of Urinary Bladder and Urethra: Advances from Bench to Patients

Abstract

Urinary tract is subjected to many varieties of pathologies since birth including congenital anomalies, trauma, inflammatory lesions, and malignancy. These diseases necessitate the replacement of involved organs and tissues. Shortage of organ donation, problems of immunosuppression, and complications associated with the use of nonnative tissues have urged clinicians and scientists to investigate new therapies, namely, tissue engineering. Tissue engineering follows principles of cell transplantation, materials science, and engineering. Epithelial and muscle cells can be harvested and used for reconstruction of the engineered grafts. These cells must be delivered in a well-organized and differentiated condition because water-seal epithelium and well-oriented muscle layer are needed for proper function of the substitute tissues. Synthetic or natural scaffolds have been used for engineering lower urinary tract. Harnessing autologous cells to produce their own matrix and form scaffolds is a new strategy for engineering bladder and urethra. This self-assembly technique avoids the biosafety and immunological reactions related to the use of biodegradable scaffolds. Autologous equivalents have already been produced for pigs (bladder) and human (urethra and bladder). The purpose of this paper is to present a review for the existing methods of engineering bladder and urethra and to point toward perspectives for their replacement.

Optimization of the current self-assembled urinary bladder model: Organ-specific stroma and smooth muscle inclusion

“…17 In the genitourinary field, most of the strategies for TE require cell-seeded matrices. 18 Clinical trials have been initiated for current self-assembled urinary bladder model a number of diseases with varying degrees of success. [19][20][21][22][23] To avoid the use of non-autologous tissues incorporated in these studies, a tissue-engineered construct was developed using UCs and DF, applying the principle of self-assembly.…”

Coming to terms with tissue engineering and regenerative medicine in the lung

“…The field of tissue engineering is geared toward developing clinically viable approaches to recreating or enhancing human organs and tissues that recapitulate both the structure and function of the native organ. For example, engineering of replacement skin tissues is now well recognized (68,187), and there has been substantial progress in other organ systems such as cartilage (45,54,107,159) and bladder (53,104,138,185,212). With regard to the lung, technologies that mimic lung function such as cardiopulmonary bypass and extracorporeal membrane oxygenation are well developed and routinely used in in-hospital settings, but they suffer from being of short-term, nonambula-tory use.…”

Bladder reconstruction: The past, present and future

“…Autologous materials have proven difficult to reproduce as a result of increased patient morbidity associated with the graft harvest (56). The increased cost in allograft and xenograft material production, in addition to the risk of disease transmission and varied mechanical strength, is crucial in their limited clinical application (56,57).…”

“…Autologous materials have proven difficult to reproduce as a result of increased patient morbidity associated with the graft harvest (56). The increased cost in allograft and xenograft material production, in addition to the risk of disease transmission and varied mechanical strength, is crucial in their limited clinical application (56,57). Furthermore, the use of natural decellularised matrices requires tissue that exhibits no principal pathological change, and is therefore unfeasible in certain patients (58,59).…”