Medical

Quantum dots made from tea leaves lay waste to lung cancer cells

Quantum dots made from tea lea...
Quantum dots made from tea leaves have been found to inhibit lung cancer growth
Quantum dots made from tea leaves have been found to inhibit lung cancer growth
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Microscope images of untreated lung cancer cells (left) and those treated with the new tea leaf-derived quantum dots (right)
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Microscope images of untreated lung cancer cells (left) and those treated with the new tea leaf-derived quantum dots (right)
Some of the researchers on the project: from left, Dr Catherine Suenne De Castro, Dr Matthew Lloyd Davies, Dr Sudhagar Pitchaimuthu
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Some of the researchers on the project: from left, Dr Catherine Suenne De Castro, Dr Matthew Lloyd Davies, Dr Sudhagar Pitchaimuthu
Quantum dots made from tea leaves have been found to inhibit lung cancer growth
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Quantum dots made from tea leaves have been found to inhibit lung cancer growth

Full of antioxidants and vitamins, tea is pretty good for you, and green tea extracts have even been used as effective carriers for cancer drugs. New research led by Swansea University has found a novel way to wring more health benefits out of the stuff, by making quantum dots from tea leaves and using them to slow the growth of lung cancer cells.

Quantum dots are semiconductor particles so small they exhibit strange electrical and optical properties, such as the ability to fluoresce in different colors, or help with certain chemical reactions. Their glowing properties mean they're showing up in TVs and solar cells, and in medical applications as biomarkers to help doctors precisely locate tumors. They're also being used to treat cancer, fight antibiotic-resistant bacteria and convert CO2 into liquid fuels.

The problem is, manufacturing them can be a costly and complicated process, and the end results can be toxic. So the Swansea team, along with researchers from Bharathiar University and K. S. Rangasamy College of Technology, set about making quantum dots out of humble tea leaves.

The scientists combined a tea leaf extract with cadmium sulfate (CdSO4) and sodium sulfide (Na2S), and then incubated the mixture until quantum dots formed. The team then exposed lung cancer cells to the tea-derived quantum dots, with the aim of testing how well their fluorescence helped light up the tumor.

"Our research confirmed previous evidence that tea leaf extract can be a non-toxic alternative to making quantum dots using chemicals," says Sudhagar Pitchaimuthu, lead researcher on the project. "The CdS quantum dots derived from tea leaf extract showed exceptional fluorescence emission in cancer cell bioimaging compared to conventional CdS nanoparticles."

Microscope images of untreated lung cancer cells (left) and those treated with the new tea leaf-derived quantum dots (right)
Microscope images of untreated lung cancer cells (left) and those treated with the new tea leaf-derived quantum dots (right)

But to the team's surprise, the nanoparticles did more than just light up the tumors – they helped destroy them. The researchers observed that the quantum dots penetrated into the cancer cells' nanopores, killing up to 80 percent of them.

"The real surprise, however, was that the dots actively inhibited the growth of the lung cancer cells," says Pitchaimuthu. "We hadn't been expecting this. Quantum dots are therefore a very promising avenue to explore for developing new cancer treatments. They also have other possible applications, for example in anti-microbial paint used in operating theaters, or in sun creams."

In the future, the researchers plan to scale up the production technique and continue to study how else these tea leaf quantum dots can be put to work.

"Building on this exciting discovery, the next step is to scale up our operation, hopefully with the help of other collaborators," says Pitchaimuthu. "We want to investigate the role of tea leaf extract in cancer cell imaging, and the interface between quantum dots and the cancer cell. We would like to set up a 'quantum dot factory' which will allow us to explore more fully the ways in which they can be used."

The research was published in the journal Applied Nano Materials.

Source: Swansea University

5 comments
jade_goat
Um..... isn't cadmium a carcinogen? I think a much safer element would be a good idea here.
guzmanchinky
We are so close to curing cancer, I can feel it. Every day you see some new breakthrough being tested.
SamB
"The researchers observed that the quantum dots penetrated into the cancer cells' nanopores, killing up to 80 percent of them." Surely the key piece of (missing) information here is how selective these quantum dots are. Do they kill 80 percent of cancer cells while killing no normal cells? Or is it 20%, 50% or 100% of normal cells? Alternatively, do these quantum dots have some special characteristic that allows them to attach to some other molecule that is extremely selective in targeting cancer cells? If none of the above, then what are we doing here.
Robert in Vancouver
Great discovery! Good thing that real scientists never say "the science is settled".
Saigvre
This is okay! Not proofed and market-ready for your casual use, but it doesn't demand special light sources at clinics, and leverages undergrad chemistry nicely; the tea extract finds cells in S-phase, preferentially messes their stuff up, and CdS is stable enough to not KO your kidneys with a little support and timed diuretics. SamB's leading questions are ready to test and corroborate, pepper with more protocol for regenerative medicine and clinical finding, forumulate, license, 20k and ship, as it were. (Let 50 crore pipelines bloom.) Even with tea polyphenols and proteins stuck on they're 3-5nm and screwing up membrane channels. (And there it is mopping up pylobacteria.) Even heme gets popped 1-2% over 3H, so intravenous delivery has a load to it. Not for use as breath freshener. I was ready to dislike it, imagining carbonizing tea leaves would leave no trace to the carbon nanodots, but that's not a step. '...we obtained tea extract from a ready source (your mom)...'. Way to grandstand, Welsh and Keralan Pharma.