Radiosynthesis and preclinical evaluation of [68Ga]Ga-NOTA-folate for PET imaging of folate receptor β-positive macrophages

摘要: Folate receptor β (FR-β), a marker expressed on macrophages, is promising target for imaging of inflammation. Here, we report the radiosynthesis and preclinical evaluation [68Ga]Ga-NOTA-folate (68Ga-FOL). After determining affinity 68Ga-FOL using cells expressing FR-β, studied atherosclerotic mice with 18F-FDG PET/CT. In addition, tracer distribution co-localization macrophages in aorta cryosections autoradiography, histology, immunostaining. The specificity was assessed blocking study folate glucosamine. As final step, human radiation doses were extrapolated from rat PET data. We able to produce high radiochemical purity moderate molar activity. Cell binding studies revealed that had 5.1 nM FR-β. Myocardial uptake 20-fold lower than 18F-FDG. Autoradiography immunohistochemistry radioactivity co-localized Mac-3-positive macrophage-rich plaques. plaque-to-healthy vessel wall ratio significantly higher Blocking verified specific FR. Based estimations data, effective dose 0.0105 mSv/MBq. Together, these findings show represents new FR-β-targeted macrophage-associated