Assessing the performance of tissue-engineered urological implants

Regenerative medicine and tissue engineering technologies are rapidly advancing with potentially broad clinical applications, including those in the field of urology. Although all structures of the lower urinary tract (ureters, bladder, sphincter, urethra) would undoubtedly benefit from utilization of tissue engineering technologies, this report will focus on applications in the bladder. In this regard, the results of both preclinical and clinical investigations support the use of engineered bladder constructs/implants for the treatment of end-stage bladder disease. Despite great progress, further optimization and utilization of this groundbreaking technology will require a more complete characterization and understanding of bladder regeneration both in vitro and in vivo. The complexity of normal tissue structure and physiology, in turn, requires a rigorous examination of the engineered 'biomimetics' to ensure that they do indeed provide the required structure, physiology and function. In this chapter we outline an algorithm for evaluation of bladder function that will be useful for such a characterization of the physiological attributes of engineered and regenerating bladders. Briefly, we propose a multidisciplinary 'vertical approach' that assesses the characteristics of bladder function/phenotype at the genetic, cellular, molecular, tissue and whole animal level. Appropriate methods and instruments are already available to this end, and in this chapter we describe both the methods and rationale for comparison of engineered/regenerating bladders with native bladder.