SRNL microsphere filled with palladium. The top of the microsphere has been removed to display contents. Credit: SRNL/Bulletin

SRNL microsphere filled with palladium. The top of the microsphere has been removed to display contents. Credit: SRNL/Bulletin

The DOE has just announced that a licensing agreement has been reached between Savannah River National Lab and specialty glass provider Mo-Sci Corp. The Missouri-based Mo-Sci will use SRNL’s unique porous-walled hollow glass microspheres as a transport mechanism for targeted drug delivery, hydrogen storage and other uses.

I take a lot of pride in this particular piece of news. When I joined the ACerS staff in early 2008, one of the first projects I developed for the Society’s magazine, the Bulletin, was a story about these PW-HG microspheres and their potential for medical and energy uses, and I have stayed in touch with one of the principle SRNL researchers behind the spheres, George Wicks, an ACerS Fellow. [Full disclosure – Wicks will become the president of ACerS in 2011].

When I first wrote about the microballoon-like spheres, I asked the hyperbolic question, “What looks like a fertilized egg, flows like water, can be stuffed with catalysts and exotic nanostructures and may have the potential to make the current retail gasoline infrastructure compatible with hydrogen-based vehicles of the future – not to mention contribute to other arenas such as nuclear proliferation control and global warming?”

Schematic diagram of PW-HG microspheres and wall porosity. Credit: SRNL/Bulletin

Schematic diagram of PW-HG microspheres and wall porosity. Credit: SRNL/Bulletin

As the diagram above indicates, the microspheres typically have a 50 micron diameter, but can be range from 2 microns to 100 microns. The shells are about 10,000 angstroms. The Bulletin story has a lot of good information about how they are made and the wide range of potential uses.

Microspheres, per se, aren’t new, but there are three things particularly important about the PW-HG microspheres. The first is that they have a network of interconnected pores engineered into the thin shells. Moreover, the SRNL researchers figured out how to customize the properties and dimensions of these pores. Thus, solid, liquid and gaseous materials can pass into and be confined within the microspheres. Several mechanisms are available to attain a controlled release of the microsphere’s contents.

The second thing is that these microspheres can be coated and/or lined with nanomaterials and structures, to, for example, improve absorbency. Proteins or fluorescent indicators can be attached to guide and monitor the spheres for drug delivery purposes or to have them act, for example, as a superior MRI contrast agent.

Finally, at a macro level, large volumes of the PW-HG spheres can be made to flow like a fluid They even look like water when poured from container to container. And, they are recyclable.

SRNL originally developed the unique microspheres as a solid-state storage method for hydrogen; they have been successfully demonstrated to store and release the gas. I am not sure if the project is still active, but at one point Toyota was involved in testing the system.

Mo-Sci’s involvement is a good sign. The company was founded in 1985 by Missouri University of Science & Technology professor Del Day, and found much success in using a different type of glass microspheres to deliver tiny amounts of strong radiation in cancer treatment. Mo-Sci’s sphere have been particularly successful in the treatment of cancerous liver tumors where the spheres can be targeted fairly precisely to deliver radiation – and have the secondary benefit of blocking the blood supply to tumors.

Mo-Sci has worked with medical institutions, such as the Cleveland Clinic, and should know the ins and outs of getting PW-HG microsphere applications to market. For more information about Mo-Sci, see my video interview with Del Day.

An article (“Porous-wall hollow glass microspheres as novel potential nanocarriers for biomedical applications”) jointly written by Wick, other SRNL researchers plus investigators at the Medical College of Georgia  will soon be published in the print version of Nanomedicine: Nanotechnology, Biology and Medicine and is now available online. The article provides more detail about the uses of the PHWG microspheres for the delivery of anti-cancer drugs.

UPDATE: The Rolla Daily News has a great story up about this, including an interview with Ted Day and others on the staff of Mo-Sci.

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