Besides being the hardest substance known to man and the most coveted of all precious stones, diamonds have also flexed their muscles in numerous areas outside the jewelry industry, from saw blades to scientific instruments.

Now we're learning that nanodiamonds may become a new therapeutic agent in the fight against cancer.

A team of researchers from South Asian University in New Delhi, India, successfully used nanodiamonds to treat tumor metastasis in mice. They found that the nanodiamonds blocked the ability of melanoma cells to migrate, while untreated tumor cells were able to pass through the membrane.

Mice administered melanoma tumor cells and then treated with carboxylic nanodiamonds showed little or no metastasis of tumors, while untreated mice saw their tumors grow and move to new areas of the body.

The findings, which were published in the journal PNAS, could signal a breakthrough in cancer treatments because almost 90% of the mortality in cancer is due to tumor metastasis (when secondary malignant growths spread to other organs from the primary site of cancer).

Based on the evidence, the authors led by Professor Rajiv Saxena, hypothesized that the tiny carbon nanodiamonds may inhibit the breaking away of cancer cells from the primary tumor mass, as well as block subsequent steps of metastasis, such as physical movement of cells and their ability to enter blood vessels.

The nanodiamonds in the study measured 2 to 8 nanometers wide, which is hard to imagine because 1 nanometer equals one-billionth of a meter. A human hair, by comparison, is between 80,000 and 100,000 nanometers thick. The National Nanotechnology Initiative points out on its website that 1 nanometer is about as long as your fingernail grows in one second.

Over time, scientists have harnessed the power of diamond's unique properties to advance so many industries. Diamonds are used to produce solar energy, computer chips, semiconductors, data storage, water purification equipment, medical devices, scientific instruments, anti-counterfeiting technology, industrial cutting tools, and much more.

Credit: Image by Bigstockphoto.com.