For the first time, researchers from Harvard University created insulin-producing beta cells by the billions using human embryonic stem cells. In animal studies, the beta cells, which deliver insulin to the bloodstream, were equivalent in almost every way to normally functioning beta cells, and could be used to level out blood sugar in the body, according to a report recently published in the journal Cell.

"We are now just one pre-clinical step away from the finish line," Doug Melton, who led the research, said in a news release. Melton has worked toward finding a cure for diabetes since his son was diagnosed as an infant 23 years ago.

The groundbreaking treatment could one day rid millions of individuals with Type 1 diabetes from a lifetime of insulin injections. Instead of the injections, patients could receive a single transplant with the newly generated cells, which would be able to release the appropriate amount of insulin.

What are beta cells?

Beta cells are unique cells in the pancreas that create, store and release insulin. Located in the area of the pancreas called the islets of Langerhans, beta cells are one of at least five different groups of islet cells that produce and secrete hormones directly into the bloodstream. Basically, they sense the level of sugar in the blood and keep it in a healthy range by delivering insulin.

However, in people with Type 1 diabetes, these cells are attacked and destroyed by the immune system.

Roadblocks in beta cell treatment

For years, the obstacle has been the supply of cells. They are difficult to produce and perhaps even harder to collect - so much so that less than 1,000 patients have undergone other kinds of stem cell procedures thus far.

With adequate sources of beta cells, scientists would be able to concentrate on the best approaches to transplantation.

Elaine Fuchs, the Rebecca C. Lancefield Professor at The Rockefeller University and a Howard Hughes Medical Institute investigator, called it one of the most important advances to date in the stem-cell field.

"For decades, researchers have tried to generate human pancreatic beta cells that could be cultured and passaged long term under conditions where they produce insulin. Melton and his colleagues have now overcome this hurdle and opened the door for drug discovery and transplantation therapy in diabetes," Fuchs said in the news release.

Although the treatment was tested only in mice and other animals and much has to be done before it can be tested on human patients, the scientists said they believed it is only a matter of time before they reach that next milestone. Melton hopes human transplantation trials using the cells will be underway within the next few years.

For more on treatment for type 1 diabetics:

New Inhaled Insulin Approved for Type 1 and Type 2 Patients
Hormone Could Change Type 1 Diabetes Treatment
Harvard Stem Cell Research May Cure Type 1 Diabetes