IMPLANTATION IN-VIVO AND RETRIEVAL OF ARTIFICIAL STRUCTURES CONSISTING OF RABBIT AND HUMAN UROTHELIUM AND HUMAN BLADDER MUSCLE

The harvest of human bladder muscle and urothelial cells with subseque nt growth may be useful for tissue replacement in genitourinary recons truction. We previously reported the development of a system for the h arvest, delivery and growth of rabbit urothelium in vivo using biodegr adable polymers. We have now expanded and adapted this system for the harvest and in vivo implantation of human bladder urothelial and muscl e cells. Synthetic polymer fibers of polyglycolic acid can serve as a scaffold and a delivery vehicle for the implantation of rabbit uroepit helial cells into athymic host animals. The polymers, which slowly deg rade in vivo, allow the urothelial cells to survive at the implant sit e. We demonstrate that polyglycolic acid polymers support the prolifer ation of rabbit urothelial cells in situ and can serve as a maleable s ubstrate for the creation of new urological structures that replace th e degrading polymer fibers. We also show that human urothelial cells a nd bladder muscle cells, when implanted on polyglycolic acid fibers, f orm new urological structures in vivo composed of both cell types. The human cell-polymer xenografts can be recovered from host animals at e xtended times after implantation. These data suggest the feasibility o f using polyglycolic acid polymers as substrates for the creation of h uman urothelial and muscle grafts for genitourinary reconstruction.