Tiny diamonds to boost treatment of chemoresistant leukaemia


US researchers bind multiple molecules of Daunorubicin with nanodiamonds

By binding multiple molecules of a common leukaemia drug with nanodiamonds, scientists from the National University of Singapore (NUS) and University of California, Los Angeles (UCLA) have boosted the delivery of the drug to leukaemic cells and retained the drug within the cells to combat the cancer.

This discovery, reported in the journal Nanomedicine: Nanotechnology, Biology, and Medicine, addresses one of the major challenges in the treatment of leukaemia where the cancer cells develop ways to pump drugs out of the body before they can do their job, particularly after they are exposed to chemotherapeutics.

Developed by Edward Chow, Principal Investigator at the Cancer Science Institute of Singapore and Assistant Professor at the Department of Pharmacology, Yong Loo Lin School of Medicine at NUS, in collaboration with Professor Dean Ho of the UCLA School of Dentistry, this innovation shows promise for greater efficacy in treating leukaemia.

Daunorubicin is currently one of the most common drugs used to treat leukaemia. The drug works by slowing down or stopping cancer cells from growing, causing many of them to die. It is also common, however, for leukaemia to become resistant to this drug after treatment.

The use of nanodiamonds offers a promising combination of biocompatibility and the capability to enhance therapeutic efficacy

One mechanism by which this opposition, commonly known as chemoresistance, happens is through the expression of drug transporter pumps in leukaemia cells that actively pump out chemotherapeutics, including Daunorubicin.

Current approaches to neutralising chemoresistance have centred on developing competitive inhibitors, but these efforts have had limited success owing to the challenges of high toxicity levels and less-than-promising results during clinical trials.

The team turned to nanodiamonds, which are tiny, carbon-based particles (2–8nm in diameter), as an option to address chemoresistance.

The team bound the surfaces of nanodiamonds with Daunorubicin, and the hybrid nanodiamond-drug complexes were introduced to leukaemic cells. They found that nanodiamonds could carry the drug to the cancer cells without being pumped out and without blocking up blood vessels.

'The use of nanodiamonds offers a promising combination of biocompatibility and the capability to enhance therapeutic efficacy,' said Chow.

'Furthermore, our initial safety tests both in vitro and in vivo indicate that they are well tolerated, which is a promising step towards continued translational development.'

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The team will now evaluate the drug-delivery complexes in clinical settings. They are also looking at applying the binding properties of nanodiamonds to other drugs.