Bridging the Gap between in Vitro and in Vivo Imaging: Isostructural Re and 99m Tc Complexes for Correlating Fluorescence and Radioimaging Studies

Citations Over TimeTop 10% of 2004 papers

Abstract

A bifunctional ligand that is capable of forming Re and 99mTc complexes as complementary fluorescent and radioactive probes was developed. The tridentate bis(quinoline) amine ligand, which is referred to as the SAACQ system, was prepared in a single step from Fmoc protected lysine in high yield. Reaction of the SAACQ ligand with [Re(CO)3Br3]2- resulted in the formation of the SAACQ-(Re(CO)3)+complex which exhibits favorable fluorescence properties including a long lifetime and a large Stoke's shift. Because the SAACQ ligand is derived from an amino acid, it can readily be linked to or incorporated within peptides as a means of targeting the probe to specific receptors. To demonstrate this feature, the SAACQ ligand and the SAACQ-Re complex were incorporated into fMLFG, a peptide that binds to the formyl peptide receptor (FPR). Uptake of the fMLF[(SAACQ-Re(CO)3)+]G conjugate into human leukocytes in vitro was visualized by fluorescence microscopy, and the observed distribution of the peptide was similar to that of a well-established fluorescent FPR probe. The corresponding Tc complex, fMLF[(SAACQ-99mTc(CO)3)+]G, was prepared in excellent yield from [99mTc(CO)3(OH2)3]+, which affords the opportunity to correlate the results of the microscopy experiments with in vivo radioimaging studies because the probes are isostructural.

Related Papers

• → Isostructural Metal–Organic Frameworks Assembled from Functionalized Diisophthalate Ligands through a Ligand‐Truncation Strategy(2013)119 cited
• → High pressure stability of β-Zr: no evidence for isostructural phase transitions(2021)8 cited
• → Insights into isostructural and non-isostructural crystals of esters of oleanolic acid and its 11-oxo derivatives(2022)4 cited
• → Isostructurality in the Guest Free Forms and in the Clathrates of 1,3,5-Triethyl-2,4,6-tris(4-halophenoxy)methylbenzenes(2011)27 cited
• → Formation of isostructural solid solutions in 2,6-disubstitutedN-phenylformamides andN-phenylthioamides(2013)6 cited