Fig. 6.

Evaluation of in vivo antitumor efficacy. a In vivo pharmacokinetics of DOX·HCl, D-NPs or D-MPNs (n = 3). b Biodistribution of DOX·HCl, D-NPs and D-MPNs in mice at 12 h post-injection. c Tumor volumes of 4T1-bearing mice after intravenous administration with saline, MPNs, DOX·HCl, D-NPs and D-MPNs at a DOX dosage of 5 mg kg⁻¹ (n = 8, *p < 0.01). The arrows indicate the times of intravenous tail vein performance. d Photographs of typical tumors collected on day 18. e Immunohistochemistry staining of 4T1 tumors. CD31-positive microvessels, Ki67-positive cells and TUNEL-positive cells were stained brown. Scale bars: 50 μm