A Magnetic Machine Plucks Pathogens from Blood

I'm curious... I know red blood cells contain hemoglobin, which to my understanding contain high levels of iron, a very magnetic substance, anyone know how this technique avoids disposing of healthy red blood cells with the pathogens? Otherwise very neat trick, but it requires known antibodies for the infectious agent in order to work, a possibly very limiting problem

You are correct about the hemoglobin containing iron. But what you are incorrect about is that hemoglobin ONLY binds 1 iron. It can't really bind more than 1 iron molecule.

To prevent pulling out the red blood cells, they probably add an antibody to the pathogen which binds to large amounts on the pathogen. They apply a weak magnetic field which is only strong enough to pull out the pathogen with the plenty of magnetic antibodies. But to pull out 1 iron molecule, you would probably need an extremely large magnetic field.

Therefore, this technique probably will be only strong enough to pull out whatever the antibody binds to. Probably because so many antibodies bind to the pathogen, or because the antibody is strongly magnetic/ferric/ferrous (?).

These beads the articles are talking about are also commonly referred to as microspheres and are usually made from latex polystyrene that encapsulates either a fluorescent dye for visualization or, in this case, a magnetic core. They are used pretty often for in vitro experiments and are now making their way into in vivo studies because of their versatility. The antibodies themselves in this case aren't magnetic, they are probably covalently bonded to the microspheres using a crosslinker like carbodiimide.

And yeah, the amount of iron oxide per bead to the amount of iron per blood cell (one molecule, aptly pointed out above) is many orders of magnitude higher. The kind of magnetic field you'd need to pull out red blood cells would be ridiculously strong.

Interesting use of these beads but I see cost being an issue, not so much for the beads, but I'm sure the antibody has to be of high purity for this application. Monoclonal antibodies are not cheap.

This article shows a fundamental misunderstanding about sepsis. It is not the bacteria themselves that are life threatening, it is the byproducts of their metabolism. Antibiotic therapy is quite effective in killing bacteria, it is the removal of the toxins produced by the bacteria that is the real issue. By the time you are symptomatic enough to qualify as "septic" this machine would not likely be any more effective than antibiotic therapy, and would require an invasive tube placed in the chest to perform the magnetic "dialysis". This therapy could be an exciting and interesting way to treat other diseases, but I don't see it becoming a practical method to treat sepsis.

The largest problem with antibiotics is that though they are usually very effective at destroying the blood pathogens, the result is that those toxins blitzwit pointed out are released into the environment in large quantities through the death of the cells. This method would be able to remove the entire cells, toxins and all. So, blitzqit, you pointed out how this is exactly why this would be an extremely effective treatment of sepsis.

Iron oxide is rust. And rust is not magnetic. They must know more about it than I do.

So I wonder what that could do for MRSA (Multiantibiotic Resistant Staphalococcus Arius.)

I seen trash separators that use a powerful magnetic field to throw non-magnetic metals off of the conveyor belt moving the trash through a automated trash recycling system. You just need a stronger magnetic field to move iron oxide.

Ellen

If the underpinning of diseases such as MS, scleroderma, and ALS are autoimmune, then perhaps this technique can be used to cure or lessen the ailment. For example, if ALS or MS is due to an infection (by a pathogen) in a problematic area (ie nervous tissue), and the body reacts by targeting the pathogen but then destroys the nervous tissue by going after the pathogen inside the tissue, then the immune reaction ends up killing the person. Perhaps monoclonal antibody (that is joined with the iron) can be made that targets the body's own self-destructive-antibody, and can then be selectively removed (along with the body's own self-destructive-antibody) by way of the magnet. A treatment that can ameliorate an overly powerful immune reaction may be worthy of further investigation. Jaguar989@comcast.net