Fig. 2.

Long-term effects of enhanced permeability and hypoxia mediated by deoxygenated PNPs in vivo. a Analysis of Evans blue accumulation in tumours 24 h after the intravenous injection of deoxygenated PNPs. Evans blue in the whole tumour was extracted and quantified by ultraviolet–visible (UV–vis) spectroscopy (n = 3). b Ex vivo fluorescence images of Evans blue (red) and 4′,6-diamidino-2-phenylindole (DAPI) (blue) staining (scale bar, 100 µm). c Quantification of Evans blue accumulation in b (n = 3). d Changes in DO after the intratumoural injection of deoxygenated PNPs and oil nanoparticles (ONPs). e Representative immunofluorescence images of hypoxia-inducible factor-1α (HIF-1α) (green) staining at 24 h after the intratumoural injection of deoxygenated PNPs and ONPs (scale bar, 100 µm). f Quantification of HIF-1α expression shown in e (n = 4). Data are presented as the mean ± s.e.m. *p < 0.05, **p < 0.01 (unpaired, two-way t tests). Source data are provided as a Source Data file