Synthesis, radiometal labeling and in vitro evaluation of a targeted PPIX derivative

In pursuit of a single molecule with potential applications for both in vitro fluorescence microscopy and in vivo PET imaging, novel targeted 69/71Ga/68Ga-protoporphyrin IX (PPIX) probes were developed. Optical analysis, fluorescence microscopy and radiolabeling with gallium-68 were performed to confirm potential applications. The use of a targeted-PPIX ring, in conjunction with 69/71Ga or 68Ga, eliminates the need for the attachment of multiple imaging tags, allowing for either in vitro fluorescent-based evaluation or in vivo nuclear-based imaging.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesized and characterized αvβ3 targeted 69/71Ga/68Ga-PPIX analogues. ► Gallium chelation does not quench fluorescence. ► In vitro fluorescence microscopy indicates specific uptake of tracer. ► Gallium-68 labeling of PPIX is optimal in a microwave reactor.