Autoaugmentation Cystoplasty Using Autologous Smooth Muscle Cell Sheet Engineering

Abstract

Purpose Current management of patients with end-stage bladder disease has been associated with significant complications. To overcome these problems, we have developed a novel approach for autoaugmentation cystoplasty using autologous smooth muscle cell (SMC) sheet as scaffoldless tissue engineeringin rabbit model. Material and Methods Viable SMCs were obtained from sixteen rabbits by partial detresorectomy and labeled with PKH-26 cell-linker and seeded on temperature-responsive culture dishes. Contiguous cell sheets were noninvasively harvested by reducing temperature and triple layer cell-dense tissues were constructed. Following detrusorectmy for autoaugmentation, transplantation of engineered tissue onto urothelial diverticulum was done. Control group underwent the same procedure except SMC-graft. At 14, 30, 90, and 180 days, animals were sacrificed to evaluate bladder reconstruction (immunofluorescence for PKH-26 and IHC for CD34, CD31, α-actin, elastin fibers, and collagen). Moreover, cystometry was performed before and 6 months after cystoplasty. Results Two weeks after SMC sheets grafting, full thickness bladder wall was seen and PKH-26 labeled SMCs were evident in muscular layer which was in accordance with positively stained cells for α-actin . Moreover, graft borders were completely aligned with the host bladder tissue in the first month. CD34+ endothelial progenitor cells and CD31+ microvessels were found in all grafts 14 days after grafting.The number of these cells increased continuously and peaked 1month after grafting. Intensity of collagen and elastin fibers reached to normal values 6 month after grafting. cystometric studys revealed significantly higher bladder capacity and compliance in grafted bladders in comparison with controls, 6 months after surgery. Conclusions Autologus SMC sheet grafting showed the potential for reliable bladder reconstruction leading to excellent bladder compliance in animal model.Our findings would pave the way toward the future tissue engineering of bladder using cell sheet technology.