Carnegie Mellon scientists develop nanogels that enable controlled delivery of carbohyd...( PITTSBURGHCarnegie Mellon University...)

PITTSBURGHCarnegie Mellon University scientists have developed tiny, spherical nanogels that uniformly release encapsulated carbohydrate-based drugs. The scientists created the nanogels using atom transfer radical polymerization (ATRP), which will ultimately enable the nanogels to deliver more drug directly to the target and to dispense the drug in a time-release manner.

The nanogels only 200 nanometers in diameter possess many unique properties that make them ideal drug-delivery tools, according to Daniel Siegwart, a graduate student in University Professor Krzysztof Matyjaszewskis laboratory at Carnegie Mellon. Siegwart will present his research Monday, Aug. 20 at the 234th national meeting of the American Chemical Society in Boston.

ATRP, a controlled living radical polymerization process, allows chemists to precisely regulate the composition and architecture of the polymers they are creating. Siegwart and colleagues used ATRP in inverse miniemulsion to make nanogels with a uniform network of cross-linked polymer chains within a spherical nanoparticle.

A uniform mesh size within the nanogels should improve the controlled release of the encapsulated drugs, said Siegwart. The major advance of this system is that ATRP allows one to prepare nanogels that are uniform in diameter. The size of the particles can be tuned, and we are currently investigating how nanogels of different sizes enter cells. The results may allow us to better understand the mechanism of endocytosis and to target specific tissues, such as cancer cells that have a more permeable membrane.

In their most recent advance, the Carnegie Mellon team incorporated the model carbohydrate drug rhodamine isothiocyanate-labeled dextran into the nanogels uniform mesh core. When the nanogels degraded, the model carbohydrate drug was released over time. The experiments were carried out with Jung Kwon Oh, a former postdoctoral associate in the Matyjaszewski lab who deve
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