Sugar used as 'Trojan Horse' to fight cancer
based on sugar nanocapsules that could be a breakthrough to treat
cancer, viral diseases and hereditary disorders.
A team of scientists from the Interdisciplinary Nanoscience Center (iNANO) at the University of Aarhus University have found that by encapsulating medicine in microscopic sugar cubes, they could induce body cells to absorb pharmaceuticals that could not normally be transported across the cell membrane.
This new technique - which basically involves using sugar nanocapsules as a "Trojan Horse" - could be an alternative to many treatments and in particular chemotherapy, the researchers claim.
While chemotherapy can be administered without difficulty, orally or intravenously, the main drawback is that healthy cells are also affected by the treatment, which leads to a number of side effects, such as hair loss, nausea and a depressed immune system.
However, with the new method, the medicines are encapsulated in microscopic containers - with a diameter of just one hundred thousandth of a millimetre - that can go through the body unnoticed, and finally deliver their load at the point of the illness, which could minimise the side effects and represent major progress in the treatment of cancer, the researchers said.
"Each cell would normally resist the entry of the foreign substance, but this is not the case with the nanocapsules because the cells cannot recognise the pharmaceutical load inside them, but think that a tasty little sugar snack is on its way," said the scientists.
The new drug delivery method has proven effective to treat arthritis in mice during early stage studies, however, arthritis is just one example. Viral infections are also a potential target for the nanocapsules; in such cases though, the treatment is not aimed at the genes in the cells of the body, but at the genome of the disease itself.
The scientists found that by filling the sugar cubes - in this experiment they used a sugar called chitosan - with a DNA copy called small iinterfering RNA (siRNA), the substance can switch off faulty genes selected among thousands of cells and therefore treat the diseases caused by these genes, by means of a mechanism called RNA interference.
"What is so brilliant about this technique called RNA interference is that the body's sick genes are passivated without affecting anything else," said the research team.
"RNA interference is probably the hottest item in biotechnology at present, with loads of high-risk capital to back it up," they added.
Chitosan, the sugar used to encapsulate the siRNA molecules, is therefore very effective in the treatment of arthritis, influenza, hepatitis as well as certain types of cancer, not because the sugar itself cures these diseases, but because it can transport a drug which does. What is more, the researchers found that after delivering the pharmaceutical directly into the cells affected, the chitosan sugar is broken down in the body and disappears without a trace.
"Because chitosan occurs in nature and is completely safe for the body, the capsules can be administered via an oral spray that leads them into the lungs, out into the blood vessels and on to the cells," said the researchers.
The Danish team has tested the new drug delivery method on mice and expects to be able to start the first preclinical trials on humans in three to four years.
The research was published in the peer-reviewed journal Molecular Therapy in October.
