Plutonium-239 (Pu-239)

Plutonium-239 is a radioactive actinide isotope that serves as a potent internal alpha-emitter and radiological hazard rather than a therapeutic target (CDC, 2018). In biological systems, it acts as a toxicant that mimics the behavior of iron by binding to the transport protein transferrin, which facilitates its distribution to the liver and mineralized bone surfaces (Taylor, 1989). Once deposited in the skeleton, Plutonium-239 exhibits an extremely long biological half-life, leading to chronic irradiation of bone-forming cells and hematopoietic marrow, which significantly increases the risk of developing osteosarcoma and leukemia (ATSDR, 2010). There are no therapeutic applications for Plutonium-239; instead, medical intervention is focused on decorporation therapy to remove the isotope from the body. The primary pharmacological agents used for this purpose are the chelators Pentetate calcium trisodium (Ca-DTPA) and Pentetate zinc trisodium (Zn-DTPA), which are FDA-approved for treating internal contamination (FDA, 2004). These agents work by forming stable, water-soluble complexes with plutonium ions, promoting their renal excretion and reducing the cumulative radiation dose to the patient (Gusev et al., 2001).

Other names

239PuPlutonium isotope 239Isotope of plutonium with mass number 239

Chelation therapy; the drugs (Ca-DTPA and Zn-DTPA) act as chelating agents that bind to plutonium ions in the extracellular fluid to form stable, water-soluble complexes that are subsequently excreted by the kidneys (FDA, 2004).