A Biodegradable Radiation Delivery System Utilizing Glass Microspheres & EDTA Chelation Therapy
Dysprosium lithium-borate (DyLB) glass microspheres have been developed as a biodegradable radiation delivery vehicle for the treatment of rheumatoid arthritis and other diseases. Radioactive microspheres of these glasses are intended to be injected into a joint infected with rheumatoid arthritis to safely deliver a localized dose (100 Gy) of beta radiation. Once injected, the microspheres react nonuniformly with body fluids. The nonradioactive, lithium-borate component is dissolved from the glass, whereas the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes chemically trapped in a solid, dysprosium phosphate reaction product that has the same size as the unreacted microsphere. The glass microspheres lose 80% of their weight after nonuniform reaction (<1 day), but the dysprosium phosphate reaction product is slowly metabolized by the body over several months. Ethylenediaminetetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product in vitro in <2 h. The dysprosium phosphate reaction product which formed in vivo in the joint of a Sprague-Dawley rat was also dissolved by EDTA chelation therapy in <1 week, without causing any detectable joint damage. The combination of DyLB glass microspheres and EDTA chelation therapy provides a unique tool for the medical community because it can deliver a large dose (>100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability.
S. D. Conzone et al., "A Biodegradable Radiation Delivery System Utilizing Glass Microspheres & EDTA Chelation Therapy," Journal of Biomaterials Research Part A, John Wiley & sons, Jan 2004.
Materials Science and Engineering
Keywords and Phrases
Biodegradable Glass; Chelation; Dysprosium; Ethylenediaminetetraacetate (EDTA); Radiation Synovectomy
Article - Journal
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