Isolation and in vitro cultivation of human urothelial cells from bladder washings of adult patients and children

To acquire urothelial cells for in vitro engineering of urothelium, biopsy specimens were taken from the urological tract. In clinical practice the number of cells harvested by biopsy are limited and the procedure requires general anaesthesia in children. The purpose of this study was to find out if bladder washings from adult patients as well as children contained enough proliferative and colony-forming uroepithelial cells to regenerate urethral mucosa in vitro, and if the cells could be stored by freezing. Bladder washings from nine children and eight adult patients were collected from patients who were having procedures that required an indwelling catheter. All cultures grew colonies of cells with a morphological appearance typical for epithelial cell growth. The cultures could be expanded to confluent, stratified sheets, and cells that stained for pancytokeratin, indicating an epithelial origin. Cells stored in -150 degrees C could be cultured and expanded in vitro. No differences were seen between cells from adults and children. Bladder washing is a non-invasive way to obtain many autologous urothelial cells. The method is reproducible and well tolerated by children. The possibility of culturing cells obtained in this way into stratified grafts provides a unique way of reconstructing the urogenital tract by "tissue engineering".