Fig. 2

NIR-II in vivo FGS in subcutaneous tumors of CRC. a Schematic diagram of real-time surgical navigation of subcutaneous tumors of CRC. b NIR-II fluorescence images of CRC tumor-bearing mice at different time points post-injected of FE-2PEG and ICG via the tail vein. Scale bar: 1 cm. c The TNR curves at different time points of (b) (n = 3, data are shown as mean ± SD). d NIR-II FGS of CT-26-Luc tumors post-injection of FE-2PEG via the tail vein at 24 h. Over 1100 nm collection. Scale bar: 1 cm. e The profiles of the tumor with skin resection (line 1), the residual tumor (line 2), and after the radical removal (line 3) of (d). f H&E staining of the primary (yellow arrow) and residual tumors (white arrow). Scale bar: 100 μm (left); Scale bar: 50 μm (right). g BLI of CT-26-Luc tumors before (left) and after the operation with the guidance of FE-2PEG (14 days) (right). h The NIR-II images of CT-26-Luc tumors after tail vein injection of ICG at 24 h; the white light and NIR-II imaging of the residual tumor; BLI of CT-26-Luc tumors before (left) and after the operation with the guidance of ICG (14 days) (right). Scale bar: 1 cm