"Green nanoparticles"
Scientists from China have turned green tea into a "syringe" for gene therapy
The substances contained in green tea can be used as a kind of "syringe" for delivering DNA and RNA molecules inside human cells and other living beings. This is written by geneticists who published an article in the journal ACS Central Science (Shen et al., Green Tea Catechin Dramatically Promotes RNAi Mediated by Low-Molecular-Weight Polymers).
"Our technique is compatible not only with RNA, but also with short segments of DNA, various DNA enzymes or their protein analogues. It opens the way for the creation of universal systems for delivering gene therapy to cells that work under any circumstances," write Cheng Jun (Cheng Yiyun) from the East China Pedagogical University in Shanghai and his colleagues.
Today, scientists are creating transgenic animals and trying to cure congenital diseases using several relatively unsafe ways to inject new DNA into cells – either by using ultrathin needles with which an egg is "pierced", or by using retroviruses, whose "combat" part is replaced with a useful genetic code.
Such operations can lead to fatal consequences as a result of banal damage to the cell membrane when a needle is inserted unsuccessfully, or as a result of the development of an immunological reaction to the virus.
Both are not an obstacle to experiments in laboratories, but this makes it extremely difficult to transfer the results of experiments into medical practice. For this reason, biologists, engineers and biotechnologists are actively looking for methods of "direct" DNA input into the cell that would not lead to its death or damage.
June and his team unexpectedly discovered a very simple, safe and effective way to deliver certain types of gene therapy to cells by experimenting with various compounds that are present in green tea extract.
Many of them, as scientists note, have not only anti-cancer and antioxidant properties, but also know how to turn into nanoparticles capable of penetrating into the cell and delivering various drugs to it. In addition, they connect well with RNA and DNA molecules and allow them to be packed into compact "tangles".
This idea prompted Chinese researchers to think that such nanoparticles can be used to "package" gene therapy and protect it from the attention of the immune system and the internal defense systems of the cell. Guided by similar considerations, geneticists made a small portion of nanoparticles from short RNA molecules that block the work of certain genes, and EGCG substances (epigallocatechin-3-O-gallate, epigallocatechin–VM gallate), one of the main antioxidants of green tea.
The scientists tested the work of these "green nanoparticles", as June and his colleagues called their brainchild, on a culture of cancer cells whose DNA was modified in such a way that they constantly emitted a green glow.
The nanoparticles successfully penetrated 80% of the cells and suppressed the work of the genes responsible for the production of light, without causing their mass death during a week of experiments. Subsequent experiments have shown that "green nanoparticles" can successfully penetrate into cells that cannot infect even the most "contagious" retroviruses.
Similarly, these nanoparticles have proven themselves in experiments on mice, suppressing the work of genes that provoke mass death of intestinal cells in acute poisoning or other problems with its work.
June and his colleagues hope that their brainchild will quickly find its place in science and medicine thanks to the use of well-studied and safe substances contained in tea and other "gifts of nature".
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