THE GREEN TEA YOU NEVER KNEW
You have probably heard that green tea is a superfood with anti-inflammatory and anti-aging properties. But did you know that green tea can also help us fight cancer?
Researchers from A*STAR’s Institute of Bioengineering and Nanotechnology (IBN) have created a new drug nanocarrier out of green tea, which can kill cancer cells more effectively than traditional methods!
They have also discovered a novel way of trapping cancer cells for analysis in order to determine the best cancer treatment that can be delivered with minimal pain and discomfort. Sounds complicated? It’s about as simple as the way a tea strainer works!
THE PERFECT DELIVERY BOYS
Inspired by the numerous health benefits of green tea, IBN researchers used a key ingredient within green tea – Epigallocatechin Gallate (EGCG) – to engineer tiny drug carriers that could deliver protein drugs to kill cancer cells in the body. This delivery process is a two-pronged approach.
First, the 'what’—green tea nanocarriers are especially effective in killing cancer cells.
A key challenge in present-day chemotherapy is ensuring that the drugs are delivered only to the cancer cells without killing surrounding healthy tissues and organs. Drug carriers act like a turbo-charged homing missile, travelling through the body, sparing healthy tissues and only zooming in on target tumour cells.
Presently, existing carriers are made of materials that have no therapeutic effects, and can cause side effects if used in large quantities.
However, by using EGCG as a carrier material, both the carrier and the drug are fighting cancer simultaneously. This synergistic effort by them both combats a larger number of cancer cells and more importantly, with no side effects.
Second, the ‘how’—the green tea nanocarriers are deliberately sized larger than the pores of normal blood vessels. This is because pores of normal blood vessels are only approximately 2-3 nanometres wide, whereas the pores of tumour blood vessels are 100 times bigger. As a result, EGCG carriers can easily enter the tumour and attack the tumour cells with cancer-killing drugs while sparing the healthy tissues.
“This is the first time that gren tea has been used as a material to encapsulate and deliver drugs to cancer cells,” said IBN Executive Director, Professor Jackie Y. Ying.
THE SILENT TRAVELLER
Another reason why these green tea nanocarriers are so effective boils down to the fact that they are exceedingly “stealthy”.
IBN researchers created a ‘stealth coat’ around the green tea nanocarrier using polyethylene glycol (PEG)-EGCG. The PEG component camouflages the carrier, preventing it from being detected and filtered out of the body by the immune system. Imagine Harry Potter creeping into Voldemort’s lair wrapped in his invisibility cloak—it’s a similar concept!
The combination of these two properties of stealth and synergy results in much more accurate tumour-targeting. In animal testings that utilised green tea nanocarriers, twice as much drugs accumulated in the tumours while drugs in other non-cancerous organs decreased by two-thirds.
“This invention could pave the way for a better drug delivery system to fight cancer,” said Dr Motoichi Kurisawa, IBN Principal Research Scientist and Team Leader.
STRAINING CANCER CELLS WITH A SIEVE?
Traditionally, doctors have to obtain tissue samples from patients for cancer diagnosis through biopsy procedures that caused much pain and discomfort. Alternatively, tumours could be detected through imaging or by physically feeling for one. However, these methods had major drawbacks—by the time the tumours could be detected, the cancer may already have been in an advanced stage.
In search of a better way of diagnosing and treating cancers, IBN researchers developed a device that could trap tumour cells circulating in the bloodstream.
How it works is similar to how we separate loose tea leaves from tea with a strainer. With pores finer than a strand of hair, this special silicon micro-sieve catches cancer cells in the sieve while allowing normal blood cells to pass through.
With this technology, cancer patients can be diagnosed using a pain-free, non-invasive and non-surgical procedure that can be completed in just two hours!
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