Lab-Grown Kidney Transplant a Success 

This week, bioengineers have come one step closer to making lab-grown organs a viable option for those in need of a transplant. Scientists at Massachusetts General Hospital implanted rats with lab-grown kidneys, which, upon transplantation, began to filter the animals' blood to make urine.

The construction of the organs began with the kidneys of recently deceased rats, which were stripped down to their underlying scaffolds of connective tissues. The organ was then regenerated by seeding the structure with a combination of human umbilical-vein cells and kidney cells from newborn rats. Together, these cells developed into blood vessels and various tissues that are specific to the kidney.

This process, which was originally developed by the same team in 2008, while clearly promising, is meant for the lab. For instance, if such technologies were applied to human organ transplants, we wouldn't have access to the same amount of tissues of recently deceased, nor would we likely be able to tap newborns for kidney cells.

This is where 3D printing will likely re-enter the scene. Rather than harvesting the kidneys of the deceased, these types of organ scaffolds have already been created through specially designed 3D printers. Furthermore, the potential for 3D-printed stem cells to then be seeded onto the lab-manufactured template could fill a key role.

As for now, however, regenerating a kidney is tricky enough without the addition of lab-made parts. After transplantation, the kidneys only produced about one-third the amount of urine from healthy kidneys. And creatine clearing, a traditional benchmark for measuring kidney function, was 36 times slower than normal.

Organ-regeneration specialist and leader of the Mass Gen team Harald Ott attributed this to the relative immaturity of the new organs, noting that they probably hadn't created the full range of cell types normal in adult kidneys.

But even if this isn't ready for the clinic, the technology already has great potential. Ott explained that most patients start to undergo dialysis when their kidney function drops below 15 percent. “If we can make a graft that works at 20 percent, that would already make patients independent of haemodialysis,” he said.

Either way, this is undoubtedly a huge step forward for regenerative medicine.

“If the work can be replicated, the scientists involved have cleare accomplished a tour de fource and deserve accolades,” said William Fissell, a nephrologist at Vanderbilt University in Nashville, Tenn.

Full story at Nature