in a recent study texas a&m university researchers described a new process to purify astatine-211 a promising radioactive isotope for targeted cancer treatment unlike other elaborate purification methods their technique can extract astatine-211 from bismuth in minutes rather than hours which can greatly reduce the time between production and delivery to the patient astatine-211 is currently under evaluation as a cancer therapeutic in clinical trials but the problem is that the supply chain for this element is very limited because only a few places worldwide can make it said dr jonathan burns research scientist in the texas a&m engineering experiment stations nuclear engineering and science center texas a&m university is one of a handful of places in the world that can make astatine-211 and we have delineated a rapid astatine-211 separation process that increases the usable quantity of this isotope for research and therapeutic purposes the researchers added that this separation method will bring texas a&m one step closer to providing astatine-211 for distribution through the department of energys isotope programs national isotope development center as part of the university isotope network details on the chemical reaction to purify astatine-211 in the journal separation and purification technology astatine is one of the least abundant elements on earth furthermore it is short-lived undergoing quick radioactive decay by releasing positively charged alpha particles to achieve nuclear stability hence astatine particularly its isotope astatine-211 is an attractive candidate for a form of radiation therapy for cancer treatment called targeted alpha-particle therapy unlike other forms of radiation that can penetrate deeper into the body damaging both healthy and cancerous tissue alpha particles travel a short distance and lose their energy thus when astatine-211 is positioned in or near cancerous tissue its emitted alpha particles travel deep enough to destroy the cancer cells but leave healthy tissue minimally harmed also the short half-life of astatine-211 or time taken for half of its atomic nuclei to decay means that it loses its radioactivity quickly and is less toxic than other radiopharmaceuticals that are long-lived burns noted however that the half-life of astatine is a double-edged sword since the element has a very low natural abundance astatine-211 is artificially made by bombarding bismuth with high-speed alpha particles once created astatine-211 begins to decay immediately he said starting the clock on how long it will last every 72 hours half of the produced astatine-211 decays away and is no longer usable for treatment said burns so the time taken from when it's produced to when it can go into the patient becomes very critical if a purification process takes 4 hours for example that means its around half of astatines half-life; you've lost a third of the material you've made in an attempt to simplify the purification process burns and his colleagues sought to use nitric acid for extracting the astatine-211 from bismuth for their experiments they filled a chromatography column that is often used for separating mixtures with tiny porous beads infused with organic chemicals called ketones next the researchers made astatine-211 by bombarding bismuth with alpha particles at the texas a&m university cyclotron institute they then dissolved the bismuth in nitric acid when they passed this solution through the chromatography column the researchers found that only astatine-211 formed a chemical bond with the ketones furthermore since the ketones are hydrophobic they were repelled away from nitric acid sticking to the beads the net effect was that bismuth passed through the column whereas pure astatine-211 remained collected within the beads this procedure the researchers found takes roughly 10 to 20 minutes unlike other astatine purification processes that can take hours although a cyclotron is needed in producing medical-grade astatine-211 burns said many hospitals are already equipped with a machine for producing other chemicals like fluorodeoxyglucose f 18 that is needed for positron emission tomography but even for hospitals that might rely on astatine-211 delivery from an offsite location the short purification procedure offers more time for transportation texas a&m university for example is in a really nice geographical location we're right in the middle of five of the top 20 largest cities in america and we're right next to one of the major cancer centers in the united states said burns we are aiming to produce purify and ship astatine in batches large enough for pre-clinical and clinical trials we are not there yet but we have made significant progress through this elegant separation technique other contributors to the research include dr evgeny tereshatov geoffrey avila kevin glennon andrew hannaman kylie lofton laura mccann mallory mccarthy dr lauren mcintosh steven schultz dr gabriel tabacaru amy vonder haar and dr sherry yennello from the cyclotron institute at texas a&m the research is funded by the united states department of energy isotope program managed by the office of science texas a&m university through the bright chair in nuclear science the texas a&m system national laboratories office and us department of energy