Cancer diagnosis: a trap of dendrimers
The polymer will help to catch atypical cells in the bloodABC magazine based on Eurek alert! –
Molecules on branched-polymer surfaces can capture rare tumor cells in blood
According to a study by scientists from the University of Illinois, Chicago, USA, cancer cells circulating in the blood in the near future can be "caught" with the help of dendrimers – branched synthetic polymers. The results of the study are published in the journal Angewandte Chemie (Dendrimer-Mediated Multivalent Binding for the Enhanced Capture of Tumor Cells).
Polymers are already used in medicine to encapsulate drugs and deliver them exactly to the place of action. However, scientists have managed to create a new polymer structure similar to a branched tree, each branch of which ends in a small sphere. The researchers also resorted to biomimicry – the surface of a synthetic polymer with the help of nanotechnology was turned into a complete semblance of a cell envelope. Such an ultra-sensitive dendrimer surface is capable of attracting and retaining a large number of cells.
Atypical cells can be separated from the tumor and transferred with the blood flow throughout the body, leading to the development of metastases. These "floating" cells are extremely difficult to catch – only a few free atypical cells can be found in a milliliter of blood of a cancer patient. During the experiment, Seungpyo Hong University professor, biopharmaceutist, the main author of the study, and his colleagues "caught" breast cancer cells circulating according to the bloodstream model using previously used linear polymers from polyethylene glycol and using branched dendrimers from polyamidoamine developed by them.
The diagram from the article in Angewandte Chemie shows cancer cells on a surface coated with polyethylene glycol and molecules "sticky" for epithelial cells (anti-epithelial cell adhesion molecule, aEpCAM), and on the same aEpCAM attached to dendrimer –VM molecules.
Scientists have found that dendrimers detect atypical cells 7 times better than linear polymers, while they are able to capture a million times more cells and hold them firmly. According to Professor Hong, the new dendrimers may soon become the gold standard for finding and capturing atypical cells in the bloodstream.
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22.11.2011