Nano missile fights cancer with green tea
It is used in cosmetics for its supposed anti-ageing properties, and incorporated into “teatox” drinks to help users shed pounds.
But for green tea to work its anti-cancer magic, between two and five litres of it must be consumed every day, studies have shown.
Patients may soon be able to tap the benefits of the popular drink in a more realistic way.
Scientists here have developed a drug-delivery system using epigallocatechin gallate (EGCG), a key ingredient in green tea, that can kill cancer cells more effectively than traditional cancer treatments.
This new drug delivery system is essentially a drug nanocarrier made using EGCG extracts. It works like a tiny missile – zipping through the body’s blood vessels to take cancer- destroying drugs to tumour sites.
And because the nanocarrier is itself made from an anti-cancer material, it delivers a double punch, boosting the rate at which cancer cells are killed.
The discovery, published this month in the prestigious journal Nature Nanotechnology, is the latest cancer breakthrough developed by the brains at the Institute of Bioengineering and Nanotechnology (IBN), a unit under the Agency for Science, Technology and Research (A*Star).
Since IBN was established in 2003, research into cancer, a major killer here, has been an important focus for its scientists.
IBN executive director Jackie Ying said the institute approaches cancer research differently.
“Many researchers and medical doctors do research on cancer biology, while IBN develops new devices and systems for diagnosis, drug screening, in-vitro toxicology and drug delivery,” she explained.
In July this year, for instance, the institute, working with the Singapore General Hospital (SGH) and National Cancer Centre Singapore (NCCS), developed a molecular test kit that can predict treatment and survival outcomes in kidney cancer patients.
The technology has been validated at SGH and the NCCS, and the institute is now seeking partners to develop and commercialise it.
And last October, researchers developed a non-toxic hydrogel that is capable of shrinking breast cancer tumours more rapidly than existing therapies.
The hydrogel was tested on tumour-bearing mice, and tumours shrank 77 per cent over 28 days. Since then, more research has been carried out on mouse models and data on these will be published soon, said IBN.
To date, IBN has published more than 970 papers and holds 500 active patents and patent applications. Approximately 10 per cent of these patents and papers are related to cancer research.
IBN’s principal research scientist and team leader, Dr Motoichi Kurisawa, who is from Hokkaido in Japan, made the latest discovery.
He said his eureka moment stemmed from his own love of green tea, which led him to wonder whether the health benefits of green tea could be one reason the Japanese have long life expectancies.
“From there, we had the idea to develop new biomaterials from green tea, which could be used as drug carriers for difficult-to-cure diseases such as cancer,” he said.
Using EGCG to manufacture a drug nanocarrier has two main benefits.
First, it reduces damage to healthy cells, which are often killed during traditional chemotherapy.
The nanocarrier cannot squeeze into the tiny pores of healthy blood vessels, which are only about two to three nanometres wide. A nanometer is a billionth of a metre.
Pores at tumour sites, however, are over 100 times larger, so the EGCG missiles can easily slip through to deposit their payload of tumour-killing drugs, while themselves killing off more harmful cells.
In tests on mice, toxic anti-cancer drugs, which typically damage the liver and kidney, were lowered by up to 70 per cent in these organs when delivered through this method, he noted.
IBN has filed a patent on the green tea nanocarrier and is developing the technology for use in patients.
Plans to continue the research on large animals are in the pipeline, and the institute is also in discussions with companies to commercialise the technology.
Said Professor Ying: “Our green tea nanocarrier not only delivers protein drugs more effectively to the cancer cells, but the combination of carrier and drug also dramatically reduced tumour growth compared with the drug alone.
“This is an exciting breakthrough in nanomedicine.”
Source: Asia One
Published: 21 Oct 2014
Category: Features, Technology & Devices
