Researchers create first heart valves in rabbits using autologous cells

Researchers in Japan have created the first heart valves using the recipients' own tissues-in rabbits. Growing replacement valves in a host with host tissue could virtually eliminate rejection when the valve is implanted.

"This is the first fabrication of an autologous heart valve inside a living body," said Kyoko Hayashida, MD, cardiovascular surgeon at the Kyoto Prefectural University of Medicine, Kyoto, Japan. "If every body organ could be recreated using autologous cells, it could solve the shortage of donated organs for transplantation and the use of costly and dangerous anti-rejection drugs."

The research team successfully grew 50 valves in rabbits and is planning to implant the first 20 valves later this year.

"Our model is very simple, just insert a polyurethane scaffolding under the skin, allow tissues to infiltrate the scaffold, and remove it a month later," Dr. Hayashida said.

The tri-leaf polyurethane scaffold is spongy material to allow tissue perfusion, sandwiched inside a circular mold. Fibroblasts invade the scaffold, completely enclosing it and growing into the proper valve shape. When removed, the valve assembly is contained in a circular ring of tissue that can be implanted into a blood vessel of the same diameter.

Early flow tests have demonstrated that the valve opens and closes normally. Future tests will investigate how well the valve resists backflow pressure as well as the potential for growth, self-repair, and regeneration after implantation.