Vorp added that biopsies carry their own risks, such as infection and other complications, and that the study needs to be replicated in a larger study group.

CNN: Scientists 'seed' cells, make new organs

"This is an exciting study showing that tissue engineering can be a viable option for complex urethral repairs, " said David A. Vorp, a professor of bioengineering and cardiothoracic surgery at the University of Pittsburgh, who was not involved with this study.

CNN: Scientists 'seed' cells, make new organs