OBJECTIVETo investigate the feasibility of constructing a capsular poly L-lactic acid (PLLA) ureteral stent seeded with autologous urothelial cells using tissue engineering methods.

METHODSThe capsular ureteral stent was constructed by subcutaneously embedding PLLA ureteral stent in the back of beagles for 3 weeks to induce the formation of connective tissue on the surfaces. After decellularization of the stent, the expanded autologous urothelial cells were seeded on the stent. The surface structure and cell adhesion of the stent were observed using HE staining, scanning electron microscope (SEM) and immunocytochemical staining. MTT assay was used to evaluate urothelial cell proliferation on the capsular PLLA ureteral stent and on circumferential small intestinal submucosa graft.

RESULTSHE staining and VIII factor immunohistochemistry revealed numerous capillaries in the connective tissue encapsulating the stent without obvious local inflammatory response. The results of SEM and immunocytochemical staining showed that the capsule contained rich collagenic fibers forming three-dimensional structures, and the seeded autologous urothelial cells could adhere and well aligned on the surface. MTT assay showed normal growth of the cells on the stent as compared with the cells grown on circumferential small intestinal submucosa graft.

CONCLUSIONThe capsular PLLA ureteral stent allows adhesion and proliferation of autologous urothelial cells and shows a potential in applications of constructing tissue-engineered ureter.