Nanodiamonds for drug delivery

Nov 12, 2007 07:47 GMT  ·  By

Ladies know why diamonds are their best friends: because they can turn people healthy. A new research carried at the Northwestern University and published in Nano Letters has revealed that nanodiamonds could be the new class of medical nanomaterials for delivering anti-cancer chemicals to cells without the negative side effects linked with currently employed delivery materials. Nanodiamonds could also be employed against tuberculosis or viruses. Using nanodiamonds to deliver chemotherapy drugs would control the exposure of other body tissues to the toxic chemicals.

Aggregated clusters of nanodiamonds have proven to be extremely effective in transporting drugs while protecting normal cells so that they are not killed, too, releasing the drug only when they have reached their target cells. Moreover, nanodiamonds have proven not to provoke cell inflammation after releasing the drug.

"There are a lot of materials that can deliver drugs well, but we need to look at what happens after drug delivery. How do cells react to an artificial material left in the body? Nanodiamonds are highly ordered structures, which cells like. If they didn't, cells would become inflamed. From a patient's perspective, this is very important," said lead researcher Dr. Dean Ho.

Ho's team turned single nanodiamonds, each only 2 nanometers wide, in clusters 50 to 100 nanometers wide. The drug filled the surface of each separate nanodiamond and is shut off in aggregates; it turns on when an aggregate enters a target cell, disaggregates and starts releasing the chemical.

The huge surface of the nanodiamonds enables the aggregates to transport about five times more chemicals than currently employed materials. Nanodiamonds could be investigated for this purpose, because they are soluble in water. Ho's team made investigations in living mice macrophage cells and human colorectal carcinoma cells, using doxorubicin hydrochloride, a common chemotherapy drug.

The team also put in contact cells to the bare nanodiamonds (free of drug) and investigated three genes connected with inflammation and one gene involved in apoptosis (cell death). The bare nanodiamonds did not affect cell growth and had no effect on long-term toxicity, inflammation or cell death.