¹⁷⁷Lu-Labeled Cerasomes Encapsulating Indocyanine Green for Cancer Theranostics

This Article reported the fabrication of a robust theranostic cerasome encapsulating indocyanine green (ICG) by incorporating 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)2000]-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid monoamide (DSPE-PEG₂₀₀₀-DOTA), followed by chelating radioisotope of ¹⁷⁷Lu. Its applications in optical and nuclear imaging of tumor uptake and biodistribution, as well as photothermal killing of cancer cells, were investigated. It was found that the obtained cerasome could act efficiently as fluorescence contrast agent as well as nuclear imaging tracer. Encapsulating ICG into cerasome could protect ICG from degradation, aggregation, and fast elimination from body, resulting in remarkable improvement in near-infrared fluorescence imaging, photothermal stability, and in vivo pharmacokinetic profile. Both fluorescence and nuclear imaging showed that such agent could selectively accumulate in tumor site after intravenous injection of the cerasome agent into Lewis lung carcinoma tumor bearing mice, resulting in efficient photothermal ablation of tumor through a one-time NIR laser irradiation at the best time window. The ability to track the uptake of cerasomes on a whole body basis could provide researchers with an excellent tool for developing cerasome-based drug delivery agents, especially the strategy of labeling cerasomes with theranostic radionuclide ¹⁷⁷Lu, enabling the ability of the ¹⁷⁷Lu-labeled cerasomes for radionuclide cancer therapy and even the combined therapy.