SUMMARY OF INVENTION
Chelator-free nanoparticles for intrinsic radiolabeling are highly coveted for whole-body disease imaging and therapeutic applications – ranging from positron-emitters, to SPECT isotopes, to therapeutic alpha-emitters. However, thus far no singular nanoparticle substrate has proven effective in binding a wide library of radioisotopes. The challenge has been similar to the specificity issues raised with conventional molecular chelators, where each element has a unique size and symmetry of electron orbitals that prohibits compatibility with a single small molecule.
MSK investigators have identified amorphous silica nanoparticles as general substrates for chelator-free radiolabeling across a wide library of medically-relevant isotopes (including 89Zr , 68Ga, 64Cu, 90Y, 177Lu and 111In). The MSK team has developed a modular kit-based procedure that can bind silica nanoparticles to an array of radioisotopes with demonstrated stability to produce labeled particles that are ready for intravenous injection. These particles have shown excellent in vivo stability and efficacy in preclinical imaging studies, with the advantage of passive accumulation/retention in cancer (in contrast to small molecules).
One-size-fits-all approach that removes need to design molecular chelating agents for each separate medical isotope, a significant cost- and rate-limiting accomplishment
Wide applicability since relevant for any given medical isotope that is oxophilic
Silica nanoparticles are inexpensive and well-characterized
Kit-based labeling approach requires minimal time and no expertise or special training
Nanoparticles continue to be an area of increasing focus in oncology. With PET and SPECT as two of the main imaging modalities that have adopted nanoparticle-based contrast agents, radiolabeled nanoparticles that do not require isotope-specific preparation are of immediate relevance for diagnostic use and hold the additional potential for therapeutic use.
Shaffer T et al. (2015) Silica Nanoparticles as Substrates for Chelator-free Labeling of Oxophilic Radioisotopes. Nano Letters (PubMed link)
AREAS OF APPLICATION
STAGE OF DEVELOPMENT
U.S. national application filed on 1/27/17; national applications pending in Canada, Europe, Japan, China
Moritz F. Kircher, MD, PhD, Laboratory Head, Memorial Hospital Research Laboratories; Assistant Attending, Memorial Hospital, MSK
Jesse Baumgartner, CFA
MSK Internal Code: SK2014-061