Near‐Infrared Intraoperative Chemiluminescence Imaging

Abstract

Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce4+ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9 pmol cm−2 of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the in vivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies.

A Novel Technique for Generating and Observing Chemiluminescence in a Biological Setting

“…No fogging or blurring of the lens was observed during the operation. We selected the commercially-available chemiluminescent agent [Ru(bpy) 3 ]Cl 2 for the development of our method based on its low price, stability in aqueous solution, well-described redox behavior, and chemiluminescent properties (Figure 2) 19 . The minimal detectable signal can be determined as described in protocol section 2 by oxidizing one drop of [Ru(bpy) 3 ]Cl 2 (100 µL, 6.9 pmol- 347 nmol in H 2 O) with (NH 4 ) 2 Ce(NO 3 ) 6 (100 µL, 25 mM) on a microscope slide.…”

“…The oxidation/reduction based chemiluminescent catalytic cycle ( C ). This figure is based on research originally published in reference 19 .…”

“…Imaging signal quantification with detection threshold (red dotted line) and background (black dotted line) ( B ). This figure is based on research originally published in reference 19 .…”

“…The white arrow points towards the right kidney. This figure is based on research originally published in reference 19 .…”

“…Quantification of chemiluminescent signals for PBS and [Ru(bpy) 3 ] 2+ -treated lymph nodes ( C ).The data represents the mean ± SD. This figure is based on research originally published inreference 19 .…”