Nanotechnology Could Help Fight Diabetes, Scientists Say
Injectable ‘toothpaste’ releases insulin (May 16)
According to an article in the journal ACS Nano, injectable nanoparticles developed at the Massachusetts Institute of Technology (MIT) may someday eliminate the need for patients with type 1 diabetes to constantly monitor their blood-sugar levels and inject themselves with insulin.
The nanoparticles were designed to sense glucose levels in the body and to respond by secreting the appropriate amount of insulin, thereby replacing the function of pancreatic islet cells, which are destroyed in patients with type 1diabetes. Ultimately, this type of system could ensure that blood-sugar levels remain balanced and improve patients’ quality of life, according to the researchers.
The MIT team set out to create a sturdy, biocompatible system that would respond to changes in glucose levels and would be easy to administer.
Their system consists of an injectable gel-like structure with a texture similar to toothpaste. The gel contains a mixture of oppositely charged nanoparticles that attract each other, keeping the gel intact and preventing the particles from drifting away once inside the body.
Using a modified polysaccharide known as dextran, the researchers designed the gel to be sensitive to acidity. Each nanoparticle contains spheres of dextran loaded with an enzyme that converts glucose into gluconic acid. Glucose can diffuse freely through the gel, so when sugar levels are high, the enzyme produces large quantities of gluconic acid, making the local environment slightly more acidic.
That acidic environment causes the dextran spheres to disintegrate, releasing insulin. Insulin then performs its normal function, converting the glucose in the bloodstream into glycogen, which is absorbed into the liver for storage.
The researchers plan to further develop the system’s delivery properties and to work on optimizing the dosage that would be needed for use in humans.
Source: MIT; May 16, 2013.