In:
Journal of Labelled Compounds and Radiopharmaceuticals, Wiley, Vol. 58, No. 5 ( 2015-05-15), p. 209-214
Abstract:
Fusarinine C (FSC), a siderophore‐based chelator coupled with the model peptide c(RGDfK) (FSC(succ‐RGD) 3 ), revealed excellent targeting properties in vivo using positron emission tomography (PET). Here, we report the details of radiolabeling conditions and specific activity as well as selectivity for 68 Ga. 68 Ga labeling of FSC(succ‐RGD) 3 was optimized regarding peptide concentration, pH, temperature, reaction time, and buffer system. Specific activity (SA) of [ 68 Ga]FSC(succ‐RGD) 3 was compared with 68 Ga‐1,4,7‐triazacyclononane, 1‐glutaric acid‐4,7 acetic acid RGD ([ 68 Ga]NODAGA‐RGD). Stability was evaluated in 1000‐fold ethylenediaminetetraacetic acid (EDTA) solution (pH 7) and phosphate‐buffered saline (PBS). Metal competition tests (Fe, Cu, Zn, Al, and Ni) were carried out using [ 68 Ga]‐triacetylfusarinine C. High radiochemical yield was achieved within 5 min at room temperature, in particular allowing labeling with 68 Ga up to pH 8 with excellent stability in 1000‐fold EDTA solution and PBS. The 10‐fold to 20‐fold lower concentrations of FSC(succ‐RGD) 3 led to the same radiochemical yield compared with [ 68 Ga]NODAGA‐RGD with SA up to 1.8 TBq/µmol. Metal competition tests showed high selective binding of 68 Ga to FSC. FSC is a multivalent siderophore‐based bifunctional chelator allowing fast and highly selective labeling with 68 Ga in a wide pH range and results in stable complexes with high SA. Thus it is exceptionally well suited for the development of new 68 Ga‐tracers for in vivo molecular imaging with PET.
Type of Medium:
Online Resource
ISSN:
0362-4803
,
1099-1344
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
1491841-9
SSG:
15,3
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