NIR-II Fluorescence /PA Imaging in vivo

NIR-II Fluorescence In Vivo Imaging System is a kind of noninvasive whole-body imaging technique. In this experiment, 200 μL MNPH2 aqueous solution (800 μg/mL) was also intravenously injected into tumor-bearing nude mice. The mice (n=3) were kept in anesthesia state using isoflurane mixed with oxygen and excited by an 808 nm internal laser at a power of 2.0 W and exposure time of 100 ms. The images collection time was set at pre-injection, 2, 4, 8, 12, and 24 h post intravenous injection of MNPH2. The fluorescence intensities of NIR-II images were analyzed using the software Image J. To verify the biodistribution and accumulation performance of MNPH2 in vivo, the tumor-bearing mice were sacrificed at 24 h after imaging and major tissues including heart, liver, spleen, lung, kidney, and tumor were imaged, and the signal intensities were quantitatively analyzed.

For in vivo PA imaging, Hep-2 tumor-bearing nude mice (n=3) were intravenously injected with 200 μL MNPH2 aqueous solution (800 μg/mL) via the tail vein. The above MSOT platform was conducted to obtain images of tumor regions at pre-injection, 2 h, 4 h, 8 h, 12 h, and 24 h post injection. The NIR excitation wavelength of MSOT scanner consists of a range of 680–980 nm. Besides, the PA signal intensities of tumor site at different points were also quantitatively analyzed.