Investigations of Urothelial Cells Seeded on Commercially Available Small Intestine Submucosa

ObjectivesTo examine adherence and viability of human urothelial cells seeded on commercially available small intestine submucosa (SIS®) specimens under serum-free conditions.Materials and methodsBefore seeding, SIS® was either washed with incubation medium or coated with collagen A, fibronectin, or pronectin. A possible influence of SIS® itself on the viability of urothelial cells was analysed with conditioned cell culture medium obtained by incubation of SIS® for 24 hours. In addition, untreated SIS® and a setting without SIS® were used as controls. Viability of urothelial cells was analysed with the WST-1 assay until day 9. Histology of seeded and unseeded SIS® specimens was investigated after Papanicolaou staining. To demonstrate urothelial cell adherence on SIS®, immunohistology was performed with a mixture of monoclonal AE1 and AE3 anticytokeratin antibodies.ResultsUrothelial cells seeded on SIS® revealed no measurable cell viability. SIS®-conditioned cell culture medium was cytotoxic for urothelial cells after 24 hours. Histology only demonstrated cell nuclei and no cytoplasm both in seeded and unseeded SIS® specimens, thus indicating porcine DNA. Expression of the cell type-specific marker proteins AE1/AE3 could not be demonstrated.ConclusionSince the commercially available SIS® specimens used contained porcine DNA residues and demonstrated cytotoxic effects on urothelial cells, SIS® is not suitable for in vitro construction of urothelial cell-matrix implants.