SCARBOROUGH — Scientists at a Maine medical research institute are receiving $6.8 million to learn how to use adult stem cells to grow kidneys.

The National Institutes of Health Researchers awarded the federal grant on Wednesday to researchers at Maine Medical Center’s Research Institute. The Scarborough-based campus will lead the research.

The lab-grown kidneys in the future could be transplanted into patients with failing kidneys.

The National Kidney Foundation says more than 4,000 people died in the U.S. last year while waiting for kidney transplants. Those who received a donated organ had to wait an average of nearly four years.

NIH also renewed a five-year $8 million grant to the institute on Wednesday to study bone marrow fat and how the cells affect other tissue.