Towards dual SPECT/optical bioimaging with a mitochondrial targeting, ^99mTc(i) radiolabelled 1,8-naphthalimide conjugate

Abstract

Highly fluorescent naphthalimide fluorophores can be radiolabelled with Tc(i)-99m for bimodal bioimaging applications.

Dual-Labelling Strategies for Nuclear and Fluorescence Molecular Imaging: Current Status and Future Perspectives

“…Pyridyl triazole scaffolds [73], imidazole derivatives [74] and porphyrin [75] have been involved in heterobimetallic coordination. Recently, Day et al reported a tracer combining the naphtalimide fluorophore and a picolylamine chelator [76]. Around 55% RCY was achieved after fac-[ 99m Tc (CO) 3 (H 2 O) 3 ] + radiolabelling.…”

Calix[4]arene-Analogous Technetium Supramolecules

“…The design and synthesis of stable and kinetically inert fac -[M­(CO) 3 ] + (M = 99m Tc/ 186/188 Re) core-based complexes have been gaining continuous research interest for the development of new radiopharmaceuticals as diagnostic and therapeutic agents. − 99m Tc is still the workhorse of nuclear diagnostics because of its ideal nuclear decay properties ( t 1/2 = 6.02 h, pure γ emitter, and E γ = 140 keV, 89%), whereas the β-emitting rhenium nuclides 188 Re ( t 1/2 = 17 h and E β = 2.12 MeV) and 186 Re ( t 1/2 = 89.3 h and E β = 1.07 MeV) have potential for therapy . Isostructural technetium and rhenium complexes are good candidates for nuclear medical theranostics, and procedures exist for the synthesis of aqua complexes [ 99m Tc/ 188 Re­(CO) 3 (H 2 O) 3 ] + as appropriate precursor molecules. ,,, Several attempts have been made toward the synthesis of organometallic technetium complexes using various types of heterocyclic ligands because of their importance in medicinal fields. − Recently, efforts have been directed toward the design and synthesis of fac -[Re­(CO) 3 ] + core-based metal–organic macrocycles, i.e., supramolecular coordination complexes or metallomacrocycles, because of their potential applications as bioimaging and anticancer agents. − …”