Engineering functional bladder tissues

Purpose: End stage bladder disease can seriously affect patient quality of life and often requires surgical reconstruction with bowel tissue, which is associated with numerous complications. Bioengineering of functional bladder tissue using tissue-engineering techniques could provide new functional tissues for reconstruction. In this review, we discuss the current state of this field and address different approaches to enable physiologic voiding in engineered bladder tissues in the near future. Materials and Methods: In a collaborative effort, we gathered researchers from four institutions to discuss the current state of functional bladder engineering. A MEDLINE (R) and PubMed (R) search was conducted for articles related to tissue engineering of the bladder, with special focus on the cells and biomaterials employed as well as the microenvironment, vascularisation and innervation strategies used. Results: Over the last decade, advances in tissue engineering technology have laid the groundwork for the development of a biological substitute for bladder tissue that can support storage of urine and restore physiologic voiding. Although many researchers have been able to demonstrate the formation of engineered tissue with a structure similar to that of native bladder tissue, restoration of physiologic voiding using these constructs has never been demonstrated. The main issues hindering the development of larger contractile tissues that allow physiologic voiding include the development of correct muscle alignment, proper innervation and vascularization. Conclusion: Tissue engineering of a construct that will support the contractile properties that allow physiologic voiding is a complex process. The combination of smart scaffolds with controlled topography, the ability to deliver multiple trophic factors and an optimal cell source will allow for the engineering of functional bladder tissues in the near future. Copyright (c) 2012 John Wiley & Sons, Ltd.