RALEIGH — A nanotechnology treatment that stabilizes blood-sugar levels for up to 10 days with a single injection has performed well in early testing, heralding what could be the next major advance in the field of diabetes.
For many patients, a single, effective weekly shot could restore the freedom and lifestyle flexibility that was lost when they received their diabetes diagnosis as children or young adults.
A research team including biomedical engineers from N.C. State University and UNC-Chapel Hill developed the system using a smart network of nanoparticles to automatically release insulin when blood-sugar levels rise, said Zhen Gu, lead author of an article published in the May 2 issue of the American Chemical Society journal Nano.
The system releases insulin to mimic the action of a healthy pancreas, said Gu, assistant professor of biomedical engineering at N.C. State.
While the findings are drawn from research in mice and must still be tested on humans, the news is encouraging for diabetes patients like Zach Arn, 16, and his sister, Chase, 9, who have Type 1 diabetes that requires painful finger pricks and blood-sugar monitoring several times each day.
Because people with diabetes lack the necessary hormone to convert sugar and other carbohydrates into fuel for their bodies, they can suffer serious health side effects, including comas or seizures, without proper treatment.
Even with the most current technology an external pump that injects insulin into the body at established intervals managing diabetes is a troublesome and time-consuming process, said Zach, a student at Middle Creek High School in Apex.
For kids as young as Chase, multiple visits to the school nurse or specially trained office staff are required each day to insure that blood-sugar levels remain normal.
I cant even get on the bus to go home unless my blood sugar is over 100, said Chase, a fourth-grader who worries when an early lunch period followed by physical education class leaves her feeing drained.
The pump used to inject insulin is typically inserted beneath the skin of the stomach or sometimes the upper arm. The location must be changed at least every three days to avoid infection.
The responsibilities of managing diabetes can easily overwhelm adults, much less busy teens such as Zach, who enjoys art, photography and riding a unicycle in his spare time.
Problems also may occur when the complex calculations for insulin formulations, which are based on meals and activity levels as well as blood-sugar readings, are inexact, leading to sickness, listlessness and limits on normal activities.
I always have to be thinking about keeping my blood sugar up, but also about not letting it skyrocket, says Zach, who has been dealing with affects of the disease since he was diagnosed at age 5.
In healthy people, blood-sugar levels are managed automatically by the pancreas, which produces insulin using beta cells. Insulin is a hormone required for glucose and other sugars to reach the bloodstream and travel to other parts of the body.
In people with Type 1 diabetes like the Arn siblings, the pancreas no longer makes insulin due to an autoimmune response that causes antibodies to attack the beta cells as if they were foreign objects, said Ali Calikoglu, a UNC associate professor of pediatrics who specializes in diabetes.
In people with Type 2 diabetes, which typically begins in adulthood and is exacerbated by high-fat and high-sugar diets and lack of exercise, the pancreas still functions, but the body no longer responds by producing insulin.
Some 26 million Americans 11 percent of the U.S. population have diabetes, according to the American Diabetes Association. North Carolina has the countrys 13th highest rate of the disease, with 1.5 million people with diabetes or pre-diabetes, a condition of abnormally high blood-sugar levels that often leads to the full-blown disease.
Insulin injection treatments for diabetes were first developed in the 1920s. About a dozen years ago, insulin pumps became available that allow injections of insulin in specific amounts through a tube that can be worn for up to three days.
By using nanoparticles, the researchers were able to sustain insulin delivery over longer periods of time.
The particles a million times smaller than a pinhead were made with a core that contains insulin and glucose oxidase enzymes. Once inside the body, the enzymes react to increase blood-sugar levels, causing the release of insulin, Gu explained.
The researchers also give the nanoparticles positive or negative electric charges so they cling together, forming a nano-network that mimics the functions of a healthy pancreas. That network can be delivered by an injection and remains effective for a week to 10 days, Gu said.
Calikoglu said other developments on the horizon for diabetes include use of nanotechnology particles to deliver insulin through an inhaler or specially coated pill, rather than injection. To be effective, insulin must bypass the stomach, where it would be digested and never make it to the bloodstream.
Beta transplantation is another area offering promise, especially if those cells could be coated to protect them from the immune systems attack, Calikoglu said
There are hurdles still, but we are on the verge of some very promising and exciting developments, he said.