Working bladders grown from progenitor cells

NEW YORK (Reuters Health) - Months after being implanted into research animals, “neo-bladders” created from progenitor cells appear to function much like natural bladders, researchers have shown.

Stem cells become progenitor cells on the way to becoming specialized cells forming particular types of tissue. Neo-bladders are created by removing bladder progenitor cells during bladder biopsies, growing the cells in culture and then seeding them onto a biodegradable bladder-shaped scaffold made out of collagen or other material.

Since the recipient’s own progenitor cells are used to create the bladder, the need for immune-suppressing drugs to prevent rejection is eliminated.

This is the “first time a complete internal organ has been regenerated and shown to grow, develop normal or near-normal function, and support life for an extended period of time,” Dr. Timothy Bertram told Reuters Health from the annual meeting of the American Urological Association in Orlando, Florida.

In the study, Bertram and colleagues from Tengion, Inc. in Winston-Salem, North Carolina, implanted neo-bladders into 14 large mammals whose original bladders were removed surgically.

Within 6 months, the neo-bladders looked and acted like natural bladders. According to Bertram, the new organs had a full blood supply system and network of nerves, and were correctly connected to other organs. Moreover, no abnormal tissues were noted and there was no evidence of an immune reaction.

“This work holds the promise that someday this technology may be used to regenerate bladders for patients who have lost bladder function,” Bertram said, or when cancer or other diseases require removal of the entire bladder.

“We anticipate that in the coming year we may begin human clinical trials in the US with the neo-bladder replacement product,” he added.