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Nanoparticle Network Acts As An Artificial Pancreas

Tuesday, May 14, 2013

May 14, 2013

By Melissae Fellet C&EN

Biomedical Engineering: Material releases enough insulin to maintain normal blood sugar levels in diabetic mice for at least 10 days.

Patients with type 1 or advanced type 2 diabetes frequently inject themselves with the hormone insulin to maintain their blood sugar levels within a healthy range. Researchers are working on creating implantable or injectable synthetic materials that release insulin in response to glucose levels, mimicking the natural action of the pancreas. A new material made from nanoparticles could improve how quickly these synthetic pancreases respond to glucose levels (ACS Nano 2013, DOI: 10.1021/nn400630x). Materials with fast response times would improve the health and quality of life for people living with diabetes, the researchers say.

Some of these previous insulin delivery methods have used slabs of hydrogels filled with the hormone. To trigger insulin release, researchers added an enzyme called glucose oxidase to the hydrogel. The enzyme consumes glucose and releases an acid. These acidic conditions cause the hydrogel to swell, releasing insulin trapped inside (J. Controlled Release 2008, DOI: 10.1016/j.jconrel.2008.08.009). But these slabs respond slowly to increasing glucose levels, because it takes a long time for the sugar to penetrate fully into the chunks of hydrogel.

Daniel G. Anderson at Massachusetts Institute of Technology and his colleagues wanted an insulin-delivery material that could respond more quickly. Their solution was to trap insulin and glucose oxidase in nanoparticles. They thought that the small size of the particles would increase the amount of enzyme exposed to glucose in the body, making the materials more sensitive to changes in levels of the sugar compared to the hydrogel slabs. Read more...