A rapidly metabolizable and enzyme-activated NIR fluorescent probe based on isophorone for imaging in vivo

Abstract

Near-infrared (NIR) fluorescent probes have excellent properties such as fast imaging speed, non-invasive, good stability and low background interference, and have great application potential in biological imaging and surgical guidance. At present, the study of fluorescent probes with long time imaging has attracted extensive attention to guide surgery, while some issues need to be considered, such as toxicity, long tissue residence time and long time for metabolism. Meanwhile, fluorescent probes with rapid metabolism tend to decay fast. Therefore, fluorescent probes need to be continuously designed and synthesized to achieve a balance of performance between suitable imaging time and reasonable metabolic rate. To this end, we design a NIR fluorescence probe that can not only complete the needs of in vivo or cell imaging in a reasonable time, but also can rapidly metabolize and shorten its residence time in the body. The synthesis of a rapidly metabolizable NIR fluorescent probe Kang-CES2 were based on isophorone for enzyme-activated imaging anaplastic thyroid cancer (ATC) in vivo. Kang-CES2 has demonstrated excellent imaging capabilities in vivo and potentiality as a spray and biopsies tool. Meanwhile, the results of intratumoral injection in mice showed that Kang-CES2 can quickly distinguish between normal and ATC tissues and continue to emit NIR light until the end of surgery. The results of tail vein injection of mice showed that Kang-CES2 can rapidly metabolize in the body within 33minutes. We believe Kang-CES2 has the potential to be a powerful fluorescent tool capable of guiding ATC surgical resection with rapid metabolism.