This day scientists are developing better ways to find Cancer cells that have broken away from the main tumor that spread the disease.
One way cancer spreads through the body by circulating tumor cells. These are cancer cells that have separated from the main tumor and began to circulate in the blood. A new tumor can be if incorporated into the rest of the body and start growing.
Then identify circulating tumor cells is an important target in cancer therapy.
This problem, however. Circulating tumor cells is very difficult to find. In a milliliter of blood is usually several billion red blood cells, many millions of white blood cells, but less than ten of circulating tumor cells.
And there's only one way to find them. The cells can be made to look different from normal blood cells. So you need a highly skilled cell biologist with a microscope and a lot of time. The needle of words and haystack do the job justice.
Various groups are seeking better ways to find circulating tumor cells and their efforts essentially fall into two categories. The first is biochemical: the trapping of cells using antibodies, binding to them. The other is mechanical filters.
Both methods have drawbacks. Antibodies can only bond with the cells, if they can get close enough. And even if circulating tumor cells are larger than red blood cells, are roughly the same size as the white blood cells, so the filters have limited success ..
Today, Markus Gusenbauer in St. Pölten University of Applied Sciences in Austria and a few friends to make some progress in this area. These guys have developed a computer model of how blood flows through a bed of magnetic beads.
When a magnetic field is applied to a bed, balls aligned in chains that form a filter with a size of the gap in particular. If a cell can pass through depends on its size and flexibility.
Model of the Austrian team takes into account the size and flexibility of red blood cells and circulating tumor cells to show how such a replaceable filter to catch the bad guys.
The idea here is that the beads are also covered by an antibody that attaches circulating tumor cells, keeps them trapped, even when the magnetic field is turned off. This method uses current technology to overcome their handicaps.
The plan is to store the beans in a room in a microfluidics lab on a chip device. A blood sample containing a handful of circulating tumor cells, but billions of other types is pumped into the chamber and the magnetic field.
This causes the beads to line up in a filter that traps the larger cells. The antibodies of the locking balls, then the target, trapping them for further study.
This is the theory. In fact, these guys have much more work to do before the system can work. For starters, the circulating tumor cells are present in a number of different flavors and mechanical characteristics of each are developed.
More serious is the problem of white blood cells. Be similar in size to that of circulating tumor cells means they could easily block the kind of filters.
But the reality is that this problem can be solved by understanding what is happening in individual cells and engineering a solution that works on this scale. So this kind of simulation is a useful first step.
Ref: arxiv.org/abs/1110.0995: A tunable filter cancer cells using magnetic beads: cell dynamics simulations fuid
