Another study was performed on 30 rabbits using bladder acellular matrix seeded or unseeded with urothelial cells. In this study bladder was removed and two ureters were sutured to constructed conduit. All 24 rabbits with cell seeded BAM survived follow-up. Multilayered epithelium covering the conduit lumen and lack of Zatebradine severe complications were TAS-102 noticed. In control group 4 rabbits died until 1 month after surgery, in two other cases fistula has appeared. Lack of epithelial layer regeneration was observed. Similar study was presented recently by the same group. One of the first attempt of ureter regeneration was performed on dogs using human or monkey umbilical cord treated with cyclophosphamide to remove morphological blood elements. Only in one case good results in long follow-up period were obtained, in other cases different degree of renal failure was observed. Other acellular natural scaffolds like SIS, decellularized ureter, scaffolds derived from vessels or synthetic materials like Gore-Tex were used. All this experiments failed because of complications or not significantly important segment reconstruction. The important aspect in ureter regeneration is to maintain ureter continuity. Small tissue section in reconstructed segment can stimulate cell layers regeneration on scaffold. Additionally peristaltic wave is not interrupted. Promising results obtained after using onlay technique shows how difficult is regeneration of whole-diameter ureter segment. Use of appropriate scaffold can stimulate its remodeling. In our study urothelium regeneration was observed on both tested scaffolds. Regeneration of smooth muscle was confirmed by immunohistochemical and Masson staining. The same effect was observed when SIS was used. Liao et al. showed lack of epithelium regeneration on unseeded BAM. Our experiment with BAM used for bladder regeneration showed urothelium regeneration on unseeded scaffold, but it has to be emphasized that urothelial layer growth is not an urinary tract regeneration. Moreover, numerous clinical trials concerning bladder reconstruction proved that urothelium self-regenerates completely, migrating from ureters even after radical cystectomy.