Figure 4.

(A) Real-time in vivo fluorescence images (Ex = 610 nm; Em = 840 nm) of GL261 tumor- bearing mice after intratumoral injection of NRA QDs and NRA@DH Gel over a 6-day period (administered dose, 0.5 mg As kg⁻¹ body weight). (B) Corresponding fluorescence signal-based CI values at tumor sites and adjacent normal brain tissue at different times post-administration (0–6 days). (C) Ex vivo fluorescence imaging of heart, liver, spleen, lung, kidneys, and tumor tissues collected after the injection of NRA@DH Gel at different times post-administration (1, 2, 3, and 6 days). (D) CLSM images of tumor cryosections after treatment with fluorescent NRA@DH Gel. Cell nuclei stained with DAPI are shown in blue and NRA@DH Gel is shown in red.