Nanodiamonds suppressed melanoma metastasis in mice
Almost 90% of cancer deaths are due to metastasis and the appearance of new tumors. That's why doctors are looking for treatments to block this process. In a new experiment, scientists from India have almost completely suppressed melanoma metastasis using nanodiamonds.
Nanodiamonds are carbon nanoparticles two to eight nanometers in diameter that can be easily functionalized, that is, attached to carboxyl or other chemical groups and drugs. When combined with a carboxyl group, nanodiamonds are more soluble in aqueous media and interact more with living cells. Overall, they are characterized by biological inertness and low toxicity, making them suitable for biomedical applications.
To find out how nanodiamonds will affect the spread of malignant tumors, took scientists from the South Asian University in New Delhi, led by Professor of Life Sciences and Biotechnology Rajiv K. Saxena (Rajiv K. Saxena). Their work was published by the journal PNAS Nexus.
From previous studies, the experts knew that actively dividing cells, such as cancer cells, are more likely to take up nanodiamonds. In addition, after treatment with carboxyl nanodiamonds, epithelial cells lost their ability to migrate through cell-permeable cellulose membranes. Therefore, the idea arose that nanodiamonds could stop the process of metastasis, in which cells migrate to new areas of the body.
Scientists treated murine melanoma cells B16F10 in culture with carboxyl nanodiamonds, then tested their ability to migrate and penetrate through polycarbonate membranes with pores with a diameter of eight microns. It turned out that nanodiamonds blocked this ability in melanoma cells, whereas untreated tumor cells were able to pass through the membrane.
In experiments with mice, the researchers injected the animals intravenously with B16F10 tumor cells. Then some of the rodents received the treatment - 50 microliters of a suspension containing 50 micrograms of carboxyl nanodiamonds, also intravenously. As a result, the latter had little or no metastasis, while in the untreated mice, tumors grew and spread to new areas. In addition, the animals treated with nanodiamonds were characterized by better survival rates.
Based on gene expression data, the researchers suggested that carboxyl nanodiamonds may prevent cancer cells from separating from the primary tumor mass and inhibit subsequent stages of metastasis. This has not previously been reported in the scientific literature.
The scientists noted that their discovery requires further study. The effectiveness of treatment with nanodiamonds should be tested on other models of tumor metastasis, and in the future - and on humans, they concluded.