Year : 2015 | Volume
: 31 | Issue : 2 | Page : 87--88
Tissue engineering and stem cell research in Urology: Is the moment yet to come?
Department of Urology, Christian Medical College, Vellore, Tamil Nadu, India
Department of Urology, Christian Medical College, Vellore, Tamil Nadu
|How to cite this article:|
Panda A. Tissue engineering and stem cell research in Urology: Is the moment yet to come?.Indian J Urol 2015;31:87-88
|How to cite this URL:|
Panda A. Tissue engineering and stem cell research in Urology: Is the moment yet to come?. Indian J Urol [serial online] 2015 [cited 2021 Aug 4 ];31:87-88
Available from: https://www.indianjurol.com/text.asp?2015/31/2/87/154293
Tissue engineering using stem cells has captured the imagination of the public and physicians alike. Like a Phoenix regenerating from its ashes, the thought of regenerating an organ by tissue engineering is indeed the stuff of legends.
Stem cell research is in itself not new. Embryonic stem cells from mouse models were first isolated in the early '80s and embryonic human stem cells in 1998.  An explosion of research into stem cells has occurred in the last 15 years. There was hope and optimism in the first few years of this century that stem cell research will provide a silver bullet that could transform the way we practice medicine.
Urology as a discipline has always been at the forefront of technological innovation. Stem cell research was no exception. There is probably a practical reason - the organs comprising the lower urinary tract are easily accessible by endoscopy with minimal morbidity. Moreover, some of the diseases that affect these organs are thought to be amenable to stem cell therapy.
Stems cells are broadly of two types - embryonic and non-embryonic (umbilical cord, fetal and adult) stem cells. Embryonic stem cells are pluripotent and can potentially form any cell type, but require complex techniques to induce their differentiation into a particular cell type. Adult stem cells are multi-potent, being capable of differentiation into multiple but not all cell types. Initially, there were ethical concerns over destroying human embryos during the use of embryonic stem cells (hES) for research. These have largely but not completely been circumvented after it was possible to induce adult stem cells to form pluripotent stem (iPS) cells. While iPS cells are similar in many ways they are not hES cells, which will still be required in very small numbers as "gold standards" and to determine which cell type will be the best for a particular condition.
While basic stem cell and tissue engineering research is expanding rapidly, translation of basic research to clinical practice has been slow. The urethra is the most studied organ in tissue engineering and stem cell research. Research on stress incontinence in both sexes has been one of the focal areas of research.  Yet, there seems to be no tissue-engineered substitute procedure for traditional implant surgery in the foreseeable future. The treatment of urethral stricture with tissue engineering is another area with significant published research. Raya-Rivera et al. in a widely quoted study created tissue-engineered autologous tubularized urethras in five boys with urethral defects. They isolated stem cells from bladder tissue and seeded them onto a synthetic tubular meshwork. The tissue-engineered tubularized urethras were then used for urethral reconstruction. They reported a 100% success over a median follow-up of 71 months.  These results however have not been replicated elsewhere. There have been efforts to produce tissue-engineered oral mucosa as a substitute for the patient's natural buccal mucosa, but the results have been disappointing.  The moot point remains that the engineered tissue must be economical, produce results that are comparable to the patient's natural buccal mucosal graft and be widely available. Unfortunately, none of these criteria can be successfully met at the moment with the available techniques.
Apart from the purely technical issues, the risk of potential malignant transformation after use of iPS cells has not been completely eliminated. While it is thought that adult stem cells have a much lower risk for malignant transformation, it has been reported in in vitro cell lines. 
Scanning the literature for tissue engineering and stem cell research in Urology throws up interesting results. While significant basic research is still ongoing, the initial enthusiasm seems to be tempered by sobering reality -- despite massive funding and dedicated research, we are not in any way closer to translation of the pre-clinical and clinical trials to everyday practice.
However, we hope the future of stem cell therapy will be bright. In this issue of the IJU, Nilima Nath et al. have published their results of in vitro stem cell research in urethral stricture disease.  The results are encouraging. The challenge will remain to actualize it into clinical practice.
Bhat et al. have published their data on penile anthropometry in north Indian children. This is an important addition to our knowledge on the standards for the Indian population.  In what is likely to be of great interest to urologists in training, Sinha and Krishnamoorthy have published a very innovative use of a vegetable model as a training tool for percutaneous nephrolithotomy. In countries where medical simulators remain largely unaffordable, such low-cost innovations can potentially transform training. 
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