Fig. 6.

Accumulation and penetration of DOX@E-PSiNPs into tumor parenchyma. a DOX content in tumor tissues and major organs of H22 tumor-bearing mice at 24 h after intravenous injection of DOX, DOX@PSiNPs or DOX@E-PSiNPs at DOX dosage of 0.5 mg kg⁻¹, or high dosage of DOX at 4 mg kg⁻¹. b Colocalization of DOX and CD31-labeled tumor vessels in tumor sections of H22 tumor-bearing mice at 24 h after intravenous injection of DOX, DOX@PSiNPs or DOX@E-PSiNPs at DOX dosage of 0.5 mg kg⁻¹. Scale bar: 200 µm. White lines represent the distance between DOX in blood vessels and DOX in tumor parenchyma. c DOX distribution profile from the blood vessels to tumor tissues on the specified white lines as indicated in b. d, e Relative DOX fluorescence intensity in GFP-positive tumor cells (d) and side population cells (e) of tumor tissues at 24 h after GFP-expressing H22 tumor-bearing mice were intravenously injected with DOX, DOX@PSiNPs or DOX@ E-PSiNPs at DOX dosage of 0.5 mg kg⁻¹, or high dosage of DOX at 4 mg kg⁻¹. Data were represented as mean ± SD (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 (two-way ANOVA with Bonferroni’s multiple comparisons test for a and one-way ANOVA with Bonferroni’s multiple comparisons test for d, e). Source data are provided as a Source Data file