Phenotypic and functional characterization of in vivo tissue engineered smooth muscle from normal and pathological bladders

Jin Yao Lai, Cheol Yong Yoon, James J. Yoo, Tina Wulf, Anthony Atala, Bradley Kropp

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


Purpose: The engineering of bladder tissue involves obtaining a biopsy from a host, expanding the cells, seeding them onto a matrix and implanting the cell-matrix composite back into the host. Clinically, cells used for these techniques may be harvested from abnormal bladders. It is not known whether abnormal bladder cells may be engineered into functionally normal tissue. We investigated the phenotypic and functional characteristics of tissue engineered bladder smooth muscle derived from patients with functionally normal bladders and functionally abnormal exstrophic and neuropathic bladders. Materials and Methods: Human smooth muscle cells derived from functionally normal bladders, exstrophic bladders and neurogenic bladders were grown, expanded and seeded onto polymer scaffolds. Sixteen cell seeded scaffolds were analyzed in vitro and 40 cell seeded scaffolds were implanted in athymic mice. The tissue engineered constructs were retrieved and analyzed at 2 weeks and 2 months. The scaffolds were evaluated immunocytochemically, histologically, with organ bath studies and with Western blot analyses. Results: Human bladder cells showed similar expression of smooth muscle marker proteins (α-actin and myosin) in vitro and after 2 months in vivo, regardless of their origin. All scaffolds showed similar muscle formation in vivo. The cell seeded scaffolds demonstrated the typical "contraction-relaxation" response to supramaximal electrical field and carbachol stimulation. There were no statistical differences among the experimental groups (normal, exstrophic, neurogenic). Conclusions: Tissue engineered muscle from normal and diseased bladders retain their phenotype in vitro and after implantation in vivo. The cells exhibited the same degree of contractility to electrical and chemical stimulation regardless of their origin. These results suggest that there are no phenotypic or functional differences between muscle cells obtained from urodynamically normal or pathological bladders, and that bladder muscle cells, regardless of their origin, may have the potential to be engineered into normal bladder tissues.

Original languageEnglish (US)
Pages (from-to)1853-1858
Number of pages6
JournalJournal of Urology
Issue number4 II
StatePublished - Oct 2002


  • Baths, bladder, tissues
  • Electric stimulation
  • Polyglycolic acid

ASJC Scopus subject areas

  • Urology


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