Compositions and associated methods for radioisotope-binding microparticles

Inventors

Reb, Philippe • Chaix, Celine

Assignees

Biosphere Medical Inc

Abstract

The present disclosure relates to polymeric materials that may be labeled with a radioisotope, to processes for producing the labeled polymeric material, and to methods of using the materials in analytical and therapeutic applications. Specifically, the disclosure relates to injectable and implantable microparticles, such as microspheres, which are associated with radioisotopes such that the microparticles are both therapeutic and detectable. The radioisotope-containing microparticles are useful for embolization and other therapeutic medical applications.

Core Innovation

The disclosure describes embolic microsphere compositions and preparation methods in which a microsphere comprises a polymerized monomer and a chelating agent. The chelating agent comprises a compound defined by Formula I, including n between 1 and 18, Xa and Xb each independently O, S or N, and R as alkyl or H, and is configured to chelate a radioisotope. The microsphere is substantially non-biodegradable and suitable for embolization.

The microsphere diameter is about 1 micrometer to about 2000 micrometers, and the microsphere comprises between about 1% and about 20% by weight of chelating agent. The monomer comprises at least one of an acrylate, acrylamide, or acrylic monomer, and the disclosure includes particular monomers such as N-[tris(hydroxymethyl)methyl]-acrylamide and sodium acrylate. The disclosure also includes chelators and classes of chelating agents selected to associate with radioisotopes and support radioisotope chelation.

The document further describes associating the prepared embolic microspheres with radioisotopes, including radioisotopes configured as beta emitters and, in some embodiments, gamma emitters. Representative chelator incorporation approaches include polymerized chelator within the microsphere and linking the chelating agent to the microsphere. The disclosed microspheres are described as enabling tumor radiotherapy and biodistribution assessment while addressing the need for embolic material that is detectable non-radiopaque by conventional imaging.

Claims Coverage

Independent claim coverage includes three distinct method scopes for preparing embolic microspheres. Across these independent claims, the key inventive features include a Formula I chelating agent in non-biodegradable embolic microspheres, chelator selection for beta-emitting radioisotope association, and substantially non-biodegradable beta-emitting Formula I chelator embolic microspheres with specified diameter and loading ranges.

Across the independent claims, the coverage is centered on non-biodegradable embolic microspheres of about 1–2000 micrometers diameter containing about 1–20 wt% of a chelating agent that is configured to chelate a radioisotope. One independent claim emphasizes a Formula I chelating agent structure with defined substituent ranges, another emphasizes a broad enumerated set of chelators selected to chelate a beta-emitter, and the third emphasizes a Formula I chelator for beta-emitting radioisotopes in substantially non-biodegradable microspheres with the same diameter and chelator loading ranges.

Stated Advantages

Documented Applications