4 Search Results

Bismuth-213 is a radionuclide of interest for targeted alpha therapy and is supplied via a radiochemical generator system through the decay of ²²⁵Ac. Radionuclide generators employ longer lived “parent” radionuclides to routinely supply shorter-lived “daughter” radionuclides. The traditional ²²⁵Ac/²¹³Bi radiochemical generator relies on an organic cation exchange resin where ²²⁵Ac binds to the resin and ²¹³Bi is routinely eluted. These resins degrade when they absorb large doses of ionizing radiation (>1 × 10⁶ Gy/mg), which has been observed when the loading activity of ²²⁵Ac exceeds 2.59*10⁹ Bq (70 mCi). Herein we report the development of an electrochemical generator for themore » supply of 213Bi that has the potential to overcome this limitation. Bismuth-213 spontaneously electrodeposits onto nickel foils in 0.1 M hydrochloric acid at 70 °C. Using this method, we were able to plate an average of 73 ± 4 % of the ²¹³Bi in solution and obtain a final ²¹³Bi recovery of 65 ± 8 % in 0.1 M citrate pH 4.5 via reverse electrolysis using titanium as the cathode. The recovered 213Bi had an average radiochemical purity of >99.8 % and was successfully used to radiolabel DOTATATE with an average radiochemical yield of 85.1 % (not optimized).« less

Thorium-226 (half-life 30.6 m) is a radionuclide of interest for use in targeted alpha therapy applications. Additionally, due to its short half-life, ²²⁶Th must be provided through a radionuclide generator system from its parent ²³⁰U (20.8 d). Furthermore, as the half-life of ²²⁶Th is very short, it should be provided in a form that is directly amenable to use in biomedical applications.

Increasing access to the short-lived α-emitting radionuclide astatine-211 (²¹¹At) has the potential to advance targeted α-therapeutic treatment of disease and to solve challenges facing the medical community. For example, there are numerous technical needs associated with advancing the use of ²¹¹At in targeted α-therapy, e.g., improving ²¹¹At chelates, developing more effective ²¹¹At targeting, and characterizing in vivo²¹¹At behavior. There is an insufficient understanding of astatine chemistry to support these efforts. The chemistry of astatine is one of the least developed of all elements on the periodic table, owing to its limited supply and short half-life. Increasing access to ²¹¹At couldmore » help address these issues and advance understanding of ²¹¹At chemistry in general. Here, we contribute an extraction chromatographic processing method that simplifies ²¹¹At production in terms of purification. It utilizes the commercially available Pre-Filter resin to rapidly (<1.5 h) isolate ²¹¹At from irradiated bismuth targets (Bi decontamination factors ≥876 000), in reasonable yield (68–55%) and in a form that is compatible for subsequent in vivo study. We are excited about the potential of this procedure to address ²¹¹At supply and processing/purification problems.« less