US researchers have effectively “grown” new urethras for five young boys in Mexico, using their own cells to grow the tubes and replace their damaged tissue.

And, after six years, these lab-grown urethras are still working. Published on Monday, the study demonstrates the ability to reproduce parts of the body which could eventually lead to repairing injuries to entire body organs.

These cell-based therapies, where scientists encourage cells to bond and form into new organs, are leading the way to potential cures to medical conditions that would otherwise affect these patients permanently.

Drugs and mechanical devices may make life easier, but cell-based therapy is proving to be an effective long-term solution.

In this particular effort, a piece of tissue is taken from the patient. The cells are nutured and encouraged to grow and multiply. This was done with two cell types – first the outer layer of the urethra cells, then the inner layer. These cells are then placed on a circular, biodegradable material and heated up to “fuse” them together.

Once the cells are fused, they are implanted into the patients, who in this study were five boys ages 10 to 14 who each had damaged urethras.

After four weeks, the boys were able to urinate effectively through their new urethras. And miraculously within three months, the lab-grown urethras had taken their place in the body, with normal cell tissue layers and smooth muscle.

The study offers potential not for just urology, but for medicine as a whole. Cell-based therapies can complement, or maybe someday replace, needs for costly drugs and mechanical devices.