Fig. 9: FA-P@MC improves plaque stability and monitors the treatment outcomes.

a Representative immunohistochemical images of MMP-9-stained aortic root sections and b quantitative analyses of MMP-9-positive areas in different groups (n = 6 mice). c Representative images of Masson’s trichrome-stained aortic root sections and d quantitative analyses of Masson’s trichrome-positive areas in different groups (n = 6 mice). e Representative immunohistochemical images of α-SMA-stained aortic root sections and f quantitative analyses of α-SMA-positive areas in different groups (n = 6 mice). Scale bars for all immunohistochemical images are 500 μm. g Representative NIR-II fluorescence images and h corresponding NIR-II intensity of the carotid arteries in atherosclerotic mice before and after either PBS or FA-P@MC treatment (n = 3 mice). Images were acquired with an 808 nm excitation wavelength and a 1000 nm long-pass emission filter. Scale bars: 1 cm. i Representative PA/US images and j corresponding PA intensity of the carotid arteries in atherosclerotic mice, presented in both sagittal and transverse views, before and after either PBS or FA-P@MC treatment (n = 3 mice). Scale bar: 3 mm. k Representative H&E-stained images and l corresponding quantitative analyses of plaque area after either PBS or FA-P@MC treatment (n = 3 mice). Scale bar: 500 μm. m Representative immunohistochemical images of α-SMA-stained aortic root sections and n quantitative analyses of α-SMA-positive areas after either PBS or FA-P@MC treatment (n = 3 mice). Scale bar: 500 μm. All data are expressed as mean ± SD. For b, d, f statistical significance was determined using one-way ANOVA for multiple comparisons; for h, j, l, n statistical significance was determined using two-tailed Student’s t-test. Source data are provided as a Source Data file.