Anti-cancer filter implant
A tiny tube inserted as a shunt on the periphery of the bloodstream is capable of selectively taking cancer cells from it, giving them the command to "die", and then releasing them back into the bloodstream, where they cease to exist. This is an impressive achievement of a group of scientists led by Michael King from the University of Rochester.
The experimental device is a tiny tube (in the picture it is wrapped around a rod). The tube has a small thickness and a decent length, to increase the contact time of flowing blood. Its inner surface is covered with a set of specific proteins.
The first, called selectins, are engaged in selective capture of cells floating through the bloodstream. There are several types of selectins, and among them there are those that bind specifically to cancer cells.
Cancer cells caught in the embrace of selectins roll along the surface of the tube. Here they fall under the action of a second protein, picked up by King and his team. This is the TRAIL protein (Tumor Necrosis Factor Related Apoptosis-Inducing Ligand), which can be simplified to translate as a factor of induced tumor apoptosis. It acts on two "death receptors" on the surface of the cell, giving it a command to self-destruct.
The cell is then released back into the bloodstream, where it will die within one to two days. And this is an important point of development: the triggered proteins, having released the cell, are again ready to accept the next "ward". "It's a little more complicated than just filtering blood," King said.
The authors of the device tested it in the laboratory on prostate and colon cancer cells (and in general, the coating can be configured for other types of cancer cells).
It turned out that the experimental tube kills 30% of tumor cells without damaging healthy cells. Such assistance in the treatment of cancer is a fundamentally new word in medicine. It is assumed that purifying the blood from a significant number of cancer cells coursing through the bloodstream will give the body a much greater chance to overcome the rest (with the assistance of other methods of treatment).
It should be noted that this work of King is a development of the research that we have discussed in detail. Scientists have studied the ability of specific proteins to glue to themselves not only cancer cells, but in general – almost any cells to choose from, depending on the goals of a particular implant. At that time, by the way, we talked in detail about the principle of action of selectins, and about the mechanism of rolling cells along the implant wall.
Now, Michael and his colleagues are pleased to note that the rolling principle allows you to increase the efficiency of the system fourfold, compared with a scheme in which cells and target proteins contact at one point.
Details of the current study can be found in an article in the journal Biotechnology and Bioengineering. Its authors add that it will take some time before the "anti-cancer shunt" reaches clinical trials. But the prospects are tempting. Such a filter will prevent metastasis and thereby increase the patient's chance of survival.
"Membrane" based on PhysOrg materials
Portal "Eternal youth" www.vechnayamolodost.ru17.12.2008