Drug-eluting Spheres for Chemotherapy

A product developed by the company BioSphere Medical (now part of Merit Medical Systems) is being tested in chemotherapy treatment of liver cancer. They are tiny beads of sodium acrylate and vinyl alcohol polymer designed to expand to four times their original diameter when placed in blood or saline solution. Additionally, they elute a drug used in traditional chemotherapy, doxorubicin. The spheres have an edge on tradition chemotherapy in two ways. First, because the spheres expand when exposed to blood, they occlude arterioles and capillaries to specific targets. This is useful in treating cancer because it starves only the targeted areas of blood, which makes the chemotherapy more effective while simultaneously keeping healthy tissue that is not targeted alive. Second, the drug is locally released instead of being introduced in a general intravenous manner. This prevents healthy tissue from being exposed to the drug, both healthy tissue that is in the organ of concern (in this case, the liver) and especially vulnerable tissues elsewhere in the body.

I found this particular medical development interesting because it introduces a relatively new concept to chemotherapy, that is, targeting areas for treatment. Additionally, it also aids chemotherapy by starving tumors of their blood supply. The localized nature of the treatment allows chemotherapy to be more effective while saving tissues that would be damaged under traditional, general chemotherapy. One of the implications is that it can allow for drugs that would normally have prohibitively deleterious effects on healthy tissue to be used. The idea of introducing embolisms to starve tumor cells is also interesting; it turns something that is normally seen as a pathology when otherwise healthy tissue is concerned into a secondary mechanism for a treatment.

-Austin Butts

http://medgadget.com/archives/2010/12/doxorubicineluting_quadrasphere_microspheres_to_be_tested_against_primary_liver_cancer.html