Nanoparticle jab may control insulin in diabetics
The technique was able to maintain normal blood sugar levels for more than a week in animal-based laboratory tests.
"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," said Dr Zhen Gu, lead author of the paper.
"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," Gu said.
Currently, diabetes patients must take frequent blood samples to monitor their blood-sugar levels and inject insulin as needed to ensure their blood sugar levels are in the "normal" range.
However, these injections can be painful, and it can be difficult to determine the accurate dose level of insulin. Administering too much or too little insulin poses its own health risks.
The new, injectable nano-network developed 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 is composed of a mixture containing 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, which breaks down the modified dextran and releases the insulin.
The insulin then brings the glucose levels under control. 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 are 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.