July 26, 2021

I, Science

The science magazine of Imperial College

Despite what many students may firmly believe, money can’t buy you happiness, right? A lot of money can, however, buy you diamonds and although I’ve never been financially stable enough to test the theory, it seems that diamonds can make women very, very happy indeed. It also seems that the bigger the diamond, the happier the girl. You don’t have to be a genius to know that giving a woman a diamond that is only 2-8 nanometers in diameter probably wouldn’t fill them with overwhelming joy. But what if that diamond could save their life?

New research published in this week’s Science Translational Medicine suggests that diamonds may soon be used to bring health as well as happiness. Carbon nanoparticles known as ‘nanodiamonds’ because of their truncated octahedral structure and multiple surface facets have been used to transport anticancer drugs into malignant tumours in mice with exciting results. When treatment of malignant tumours fails, the cause is almost always the same. 90% of treatment failures occur because cancer cells are able to pump out the anticancer drugs before they have had any significant detrimental effect on the cancer. Attaching the drugs to nanodiamonds could potentially overcome this problem.

The cellular transport proteins in cancer cells, which usually pump out the offending anticancer drugs, are unable to carry the nanodiamond and so the drug remains within the cancer cell long enough to fight. In the study, led by Dean Ho, a biomedical engineer at Northwestern University in Illinois, the anticancer drug doxorubicin was attached to nanodiamonds and this new compound was used to treat mice suffering from liver cancer. Two days later, the levels of doxorubicin within the tumours was tested and compared to levels in tumours of mice that had been treated with doxorubicin alone. The results were extremely significant. Levels of doxorubicin were found to be ten times higher in mice treated with the nanodiamond-doxirubicin compound compared with mice that had been treated with pure doxorubicin. Those mice that had received this compound also survived longer, as their tumours shrank at a much higher rate than those treated with just doxorubicin.

The success of the compound did not end there. Ho’s team then used the compound to battle a form of breast cancer which has, in the past, proven to be highly resistant to doxorubicin. Extremely high doses of doxorubicin, which would normally be fatal to the recipient mouse, were combined with the nanodiamond and successfully reduced the toxicity of the drug by releasing it more slowly. Not only were the mice able to survive the high doses of doxorubicin, but combining it with nanodiamonds also prevented many of the usual side effects of the drug as the mice did not even lose weight following this aggressive treatment.

Though other nanoparticles are already being used for drug delivery, nanodiamonds have a much more versatile surface structure: each facet possesses different properties, such as electrical charge. Where one facet is neutral, the drug can be attached, while other facets retain an electrostatic charge (giving them the ability to disperse in fluids, which administers the drug more effectively). Nanodiamonds are also cheap to produce on a large scale, although Bioengineer Tim Deming from the California NanoSystems Institute maintains that this production process needs refining before they could be used for cancer treatment in humans.

Once this process is refined, testing the effectiveness of nanodiamond compounds in treatment of human cancers can begin. What these ‘unseen’ diamonds lack in size, it seems they may more than make up for in strength; perhaps the days of competition for who has the biggest diamonds are drawing to a close.