In vivo cancer imaging by poly(ethylene glycol)- b -poly(ɛ-caprolactone) micelles containing a near-infrared probe

Abstract Noninvasive near-infrared (NIR) fluorescence imaging is a promising technique for the intraoperative assessment of solid tumor removal. We incorporated a lipophilic NIR probe, 1,1′-dioctadecyltetramethyl indotricarbocyanine iodide (DiR), in poly(ethylene glycol)- b -poly(ɛ-caprolactone) (PEG- b -PCL) micelles, resulting in DiR solubilization in water, occupying nanoscopic PEG- b -PCL micelles. DiR in a self-quenched or nonquenched state showed different kinetics of release from PEG- b -PCL micelles in vitro; however, both obtained high tumor delineation (tumor-to-muscle ratio of 30–43 from collected organs). These results suggest that PEG- b -PCL micelles with DiR are a promising nanosized imaging agent that will provide a basis for enhanced surgical guidance via NIR visualization of tumors. From the Clinical Editor In this paper, noninvasive near-infrared fluorescence imaging coupled with specific lipophilic probes is discussed as a promising technique for intraoperative assessment of solid tumor removal, leading to optimized outcomes for in toto removal of tumors.