Fig. 8

In vivo efficacy of nanoparticle-encapsulated WIP1 and miR-21 inhibitors in trastuzumab-resistant breast tumor models. a Relative cell viability of trastuzumab-resistant HER18R treated with indicated doses of nanoparticles encapsulating WIP1 or miR-21 inhibitors for 72 h. b In vivo whole animal imaging of ICG fluorescence at 1 h, 6 h, and 24 h, respectively, after intravenous injection of saline, free ICG and NP-ICG nanoparticles. Ex vivo imaging of ICG fluorescence of tumor together with five important organs collected when the mice were sacrificed at 24 h post-injection. The arrows indicate the locations of tumors in mice. c–e Gross tumor images (c), tumor growth curves (d) and tumor weight (e) of xenograft tumors derived from orthotopically implanted trastuzumab-resistant HER18R cells. Once tumors were palpable, mice were randomly divided to 4 groups and then treated with either control, WIP1 (5 mg kg⁻¹) and/or miR-21 (1 mg kg⁻¹) inhibitor nanoparticles (twice per week) intravenously. f, g Quantification of cell proliferation (Ki-67 staining, f) and apoptosis (cleaved caspase-3 staining, g) in the abovementioned xenografted tumor tissues. **p < 0.01; ***p < 0.001; unpaired 2-tailed t-test was used e–g. Data are presented as mean ± SD