Position for site-specific attachment of a DOTA chelator to synthetic affibody molecules has a different influence on the targeting properties of 68Ga- compared to 111in-labeled conjugates.

摘要: Affibody molecules, small (7 kDa) scaffold proteins, are a promising class of probes for radionuclide molecular imaging. Radiolabeling molecules with the positron-emitting nuclide 68 Ga would permit use positron emission tomography (PET), providing better resolution, sensitivity, and quantification accuracy than single-photon computed (SPECT). The synthetic anti-HER2 ZHER2:S1 molecule was conjugated DOTA at N-terminus, in middle helix 3, or Cterminus. biodistribution Ga- 111 In-labeled directly compared NMRI nu/nu mice bearing SKOV3 xenografts. position chelator strongly influenced tracers, influence more pronounced Ga-labeled counterparts. best variant Ga[DOTA-A1]-ZHER2:S1, which provided tumor uptake 13 6 1 %ID/g to blood ratio 39 12 2 hours after injection. In-[DOTA-A 1]-ZHER2:S1 In-[DOTA-K 58]-ZHER2:S1 were equally good this time point, 15 16 range 60 80. In conclusion, selection can be used optimization their imaging properties. This may important development Affibody-based other protein-based probes.