CHICAGO, July 7 (Xinhua) -- Research in mice at the Washington University School of Medicine in St. Louis shows that genetic material can be delivered to damaged cells in the kidneys.

The researchers focused on whether adeno-associated virus (AAV), a relative of the virus that causes the common cold, could deliver genetic material to targeted kidney cells.

The researchers evaluated six AAV viruses, both natural and synthetic, in mice and in stem-cell-derived human kidney organoids. A synthetic virus, Anc80, created by one of the researchers, proved successful in reaching two types of cells that contribute to chronic kidney disease. These cells secrete proteins that gum up the organ and cause irreversible damage.

The researchers also showed that the genetic material carried by Anc80 was transferred successfully to the targeted kidney cells.

"This was a happy surprise," said senior author Benjamin D. Humphreys, director of the Division of Nephrology at Washington University. "We were not expecting this."

"The interesting thing about the adeno-associated viruses is that they persist in the body for many months, potentially giving a therapeutic gene a chance to do its work," Humphreys said. "Chronic kidney disease is a slowly progressive disease so that is an advantage. After many more years of research, we could envision that patients would need injections maybe twice a year as opposed to every week, like with chemo."

"There has been so little innovation in kidney treatment," he said. "We believe this is a positive step forward."

Humphreys cautioned that researchers are still early in the process. In future research, scientists will encounter several challenges, such as the need to identify a gene that can extensively correct damaged kidney cells. Another issue involves refining the boundaries of gene delivery to prevent delivery of the synthetic virus to other organs.

Kidney disease affects 30 million Americans. Current treatments for end-stage disease mostly are limited to dialysis and kidney transplant.

The findings were published July 5 in the Journal of the American Society of Nephrology.