(Miami-AFP) - An experimental "smart insulin" that acts for 14 hours has shown promise in mice and could be tested in people with type 1 diabetes in two years, researchers said Monday.

The product, known as Ins-PBA-F and developed by biochemists at the University of Utah, self-activates when blood sugar soars, according to the research published in the Proceedings of the National Academy of Sciences.

Tests on mice with a form of type 1 diabetes showed that one injection could "repeatedly and automatically lower blood sugar levels after mice are given amounts of sugar comparable to what they would consume at mealtime," said the study.

The drug closely mimicked the way the bodies of normal mice would return their blood sugar levels to normal after eating.

"This is an important advance in insulin therapy," said co-author Danny Chou, assistant professor of biochemistry at the University of Utah.

"Our insulin derivative appears to control blood sugar better than anything that is available to diabetes patients right now."

People with type 1 diabetes must constantly monitor their blood sugar and manually inject themselves with insulin when needed.

Any mistake or lapse can lead to complications, including heart disease, blindness or even death.

Ins-PBA-F is a chemically modified version of a naturally occurring hormone.

It differs from other "smart insulin" products in development that use a protein-based barrier, such as a gel or coating, that inhibits insulin when blood sugar is low.

After more long-term safety tests in lab animals, the first human safety trials could begin in two to five years.