The research was conducted by researchers at North Carolina State University, the University of North Carolina at Chapel Hill, the Massachusetts Institute of Technology and Children's Hospital Boston.
Dr. Zhen Gu, lead author of a paper describing the work and an assistant professor in the joint biomedical engineering program at NC State and UNC Chapel Hill, said that their team has 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.
He said that they had tested the technology in mice and one injection was able to maintain blood sugar levels in the normal range for up to 10 days.
When a patient has type 1 diabetes, their body does not produce sufficient insulin, a hormone that transports glucose from the bloodstream into the body's cells and this can cause a host of health effects.
The new, injectable nano-network is composed of a mixture that contains nanoparticles with a solid core of insulin, modified dextran and glucose oxidase enzymes.
When the enzymes are exposed to high glucose levels they effectively convert glucose into gluconic acid that breaks down the modified dextran and releases the insulin.
The insulin then brings the glucose levels under control and the gluconic acid and dextran are fully biocompatible and dissolve in the body.
Each of these nanoparticle cores is given either a positively charged or negatively charged biocompatible coating, the positively charged coatings are made of chitosan (a material normally found in shrimp shells), while the negatively charged coatings are made of alginate (a material normally found in seaweed).
When the solution of coated nanoparticles is mixed together, the positively and negatively charged coatings get attracted to each other to form a "nano-network."
Once injected into the subcutaneous layer of the skin, the nano-network holds the nanoparticles together and prevents them from dispersing throughout the body. Both the nano-network and the coatings are porous, allowing blood - and blood sugar - to reach the nanoparticle cores.
Gu said that this technology effectively creates a "closed-loop" system, which mimics the activity of the pancreas in a healthy person, releasing insulin in response to glucose level changes.
The paper was published in ACS Nano.
--ANI (Posted on 04-05-2013)