Fig. 7: Enhanced tumor accumulation and penetration of anti-PD-1 antibody by Met@Man-MPs.

a Schematic schedule for tumor accumulation and penetration analysis of anti-PD-1 antibody in H22 tumor-bearing mice. b Relative anti-PD-1 antibody content in different tissues and tumors of H22 tumor-bearing mice after treatment with Cy5-labeled anti-PD-1 antibody (100 µg per mice) and Met@Man-MPs pretreated with or without Bati (0.6 mg mL⁻¹) at the Met dosage of 10 mg kg⁻¹ indicated in (a). Data are presented as mean ± s.d. (n = 4 mice per group; one-way ANOVA followed by Tukey’s HSD post-hoc test). c Colocalization of Cy5-labeled anti-PD-1 antibody (red) with endothelial cells labeled with FITC-conjugated CD31 antibody (green) in tumor sections of H22 tumor-bearing mice after treatment with Cy5-labeled anti-PD-1 antibody (100 µg per mice) and Met@Man-MPs pretreated with or without Bati (0.6 mg mL⁻¹) at the Met dosage of 10 mg kg⁻¹ indicated in (a). The nuclei were stained by DAPI (blue). Images are representative of 3 biologically independent mice. Scale bars: 50 μm. d Ratio of Cy5 in tumor parenchyma to that within blood vessels as indicated in c. Data are presented as mean ± s.d. (n = 15 fields for 3 mice; one-way ANOVA followed by Tukey’s HSD post-hoc test). e Time-lapse imaging of Cy5 extravasation and penetration into tumor tissues of H22 tumor-bearing mice after the mice were intravenously injected with Met@Man-MPs pretreated with or without Bati (0.6 mg mL⁻¹) at the Met dosage of 10 mg kg⁻¹ every other day for two times and then intravenously injected with Cy5-labeled anti-PD-1 antibody (100 µg per mice, red). The vasculature was labeled with fluorescein-labeled tomato lectin (green). The arrows indicated the extravascular anti-PD-1 antibody. Images are representative of two biologically independent mice. Scale bars: 10 μm. f Extravascular Cy5 fluorescence normalized by the maximum Cy5 fluorescence within blood vessels at 10 min post-injection (expressed as %Vmax) indicated in e. Data are presented as mean ± s.d. (n = 10 fields for 2 mice; two-way ANOVA followed by Bonferroni’s multiple comparisons post-test). Source data are provided as a Source Data file.