Fig. 6: Biodistribution, biocompatibility, and antitumour effects in vivo.

a Schematic diagram of the in vitro BBB model. b The transendothelial electrical resistance (TEER, Ω·cm²) values in the in vitro BBB model at different time points after incubation with formulations (n = 3 independent experiments). c Transport ratios of different formulations determined by detecting Cy5.5 fluorescence intensity in the apical chamber and basolateral chamber after 4 h of incubation in the in vitro BBB model (n = 3 independent experiments). d In vivo Cy5.5 fluorescence images of CT2A-bearing mice at different time points after intravenous injection of different formulations. Ex vivo (e) Cy5.5 fluorescence images and (f) quantitative histogram of the fluorescence intensity of both the CT2A-bearing brain and major organs (including the heart, liver, spleen, lung, and kidney; n ≥ 3 mice for each group). g Experimental design of therapeutic FBFO@HM@aSPP intervention in a CT2A tumour model (n = 5 mice per group). h Representative bioluminescence images (left) and fluorescence intensity quantification (right), as well as (i) Kaplan–Meier survival curves of luciferase-expressing CT2A-bearing mice subjected to different treatments (n = 5 mice per group). j H&E staining of brain tumour tissues from CT2A tumour-bearing mice subjected to various treatments. Scale bar, 2 mm. CLSM images of (k) Ki67 (scale bar, 50 μm), (l) CD44 (scale bar, 20 μm) and (m) CALR (scale bar, 20 μm) staining of brain tumour tissues from CT2A tumour-bearing mice subjected to various treatments. All the data are presented as the means ± SDs. The p values were determined via two-tailed one-way ANOVA with a Tukey post hoc test (c, h). For i, p values are calculated via the log-rank (Mantel‒Cox) test. p > 0.05, not significant (ns), *p < 0.05; **p < 0.01; ***p < 0.001; and ****p < 0.0001. Source data are provided as a Source Data file.