Sheath anticancer agent made of polymer, and a green tea component, is an extremely efficient method for delivering high doses of the drug in the tumor showed team A * STAR. They have demonstrated the potential of the system by using it to inhibit the growth of liver tumors in mice.
Molecules some polymers are water inlet (hydrophilic) at one end and water-repellent (hydrophobic) - on the other. When they are placed in water, such polymers form nano-sized beads known as micelles with their hydrophilic ends facing outwards. These micelles make excellent vehicles for the transport of drugs to the desired area of the body. This is due to the fact that the insoluble medicament can be hidden in the micelle hydrophobic core without allowing it to harm other tissues until it is released within the tumor, whereas the hydrophilic outer surface of the micelle allows to move in the bloodstream. Micelles can be developed to target tumors using different mechanisms.
Although polymeric micelles have been well studied in clinical trials, they tend to fall short of expectations. Their poor performance was to their low load of drugs - often they can only carry about 10 percent of their total weight - and their instability, which causes them to break down and unload their cargo before reaching the target, inflicting damage to healthy tissue.
Now, Motoichi Kurisava in Institute of Bioengineering and Nanotechnology A * STAR and colleagues showed that a micelle with the hydrophilic tips made of polymer poly (ethylene glycol), commonly known as PEGs and hydrophobic tails epigallocatechin gallate (EGCG) - a component of green tea - overcame both Problems. Researchers have found that the micelles have an extremely high ability to load more than 80% of drugs for anticancer drug doxorubicin. They also are stable in the bloodstream.
"We did not expect such a high load capacity, - says Kurisava. "Usually, the micelles become unstable, as you increase their capacity to load drugs, and yet our micellar nanocomplexes dissolve in water. It was a surprise for us as well as for some of the reviewers who have asked us to check our work. But we have confirmed the results. "
The results also demonstrated the versatility of micelles. "In a previous study, we used a drug against protein antibodies, this time we used a small drug," - says Kurisava. "This is an advantage over existing systems: EGCG may interact with various types of drugs, including antibodies, proteins, small drugs, and even nucleic acid. However, the specific polymeric drug carriers must be designed to encapsulate specific drugs. "
In addition, EGCG that is useful for the transport of anticancer drugs, also known as a powerful antioxidant with anticancer properties. the team is now studying the synergy.