May 4, 2013
Nano-Network Could Internally Trigger Insulin Release In Diabetics
redOrbit Staff & Wire Reports - Your Universe Online
Newly-developed nanoscale particles could be injected into the bodies of diabetic patients, triggering insulin release when glucose levels rise, maintaining normal blood sugar levels for at least a week, claims a new study published online Thursday by the journal ACS Nano.
The particles were developed by researchers from North Carolina State University (NCSU), the University of North Carolina at Chapel Hill (UNC), the Massachusetts Institute of Technology (MIT) and Children´s Hospital Boston, and they could lessen the need for type 1 diabetes patients to inject insulin to keep their blood glucose levels in the normal range.
Those injections are painful, they explain, and it can be difficult to administer the correct dosage — which can also lead to health problems, should too much or too little insulin be injected. However, their new injectable nano-network is made of up nanoparticles with a solid insulin core, modified dextran, and glucose oxidase enzymes.
When the enzymes are exposed to elevated glucose levels, they convert the sugar into gluconic acid, which in turn breaks down the dextran and releases the insulin into the body. The hormone brings the glucose levels back down into the normal range, while the gluconic acid and dextran dissolve in the body.
“We´ve created a ℠smart´ system that is injected into the body and responds to changes in blood sugar by releasing insulin, effectively controlling blood-sugar levels,” Dr. Zhen Gu, lead author of the study and an assistant professor in the joint biomedical engineering program at both NC State and UNC Chapel Hill, said in a statement. “We´ve tested the technology in mice, and one injection was able to maintain blood sugar levels in the normal range for up to 10 days.”
According to Gu and his colleagues, each of their nanoparticle cores is given either a positively or negatively charged biocompatible. The positive coating is made out of a material normally found in shrimp shells known as chitosan, while the negative coating are made from alginate, a substance typically found in seaweed.
The cores are then attracted to each other´s charge in order to create what the researchers refer to as a “nano-network.” This network is then injected into the subcutaneous layer of the skin, where it holds the nanoparticles in place and keeps them from spreading throughout the body. Both the coatings and the nano-network itself are porous, allowing blood and glucose to reach the nanoparticle cores, the researchers said.
“This technology effectively creates a ℠closed-loop´ system that mimics the activity of the pancreas in a healthy person, releasing insulin in response to glucose level changes. This has the potential to improve the health and quality of life of diabetes patients,” explained Gu. He and his colleagues are said to be in discussions to start clinical trials involving the technology in human patients.