Fig. 5: Antitumor effect in an orthotopic 4T1 breast cancer model.

a Schematic illustration of the assessment protocol evaluating antitumor efficiency. b Visual representation of tumor progression in treated mice, with tumors outlined by a yellow dashed line. c, d Comparison of tumor progression and weight post-treatment (n = 5 mice). e H&E and Ki67 immunohistochemistry in tumor sections, red arrows: regions of necrotic tumor cells, blue arrows: viable tumor cells. n = 5 mice. f, g Flow cytometry analysis of activated DCs (CD80⁺CD86⁺) in LNs and tumors (n = 5 independent experiments). h Flow cytometry analysis of CD3⁺CD8⁺ T cells in LNs (n = 5 independent experiments). i Flow cytometry analysis of CD8⁺ T cells within CD45⁺ cells from tumors (n = 5 independent experiments). j, k Flow cytometry analysis of Tregs (CD3⁺CD4⁺Foxp3⁺) in LNs and tumors (n = 5 independent experiments). CLSM imaging of (l) XBP1s and (m) BODIPY in LNs (n = 3 independent experiments). G1: PBS, G2: DOX, G3: DOX + SS-Toy, G4: DOX+OMVs@SS-Toy, G5: DOX+EMVs@SS-Toy, G6: DOX+aPD1+EMVs@SS-Toy. Data are presented as mean ± SD. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 and ^****P < 0.0001 by two-tailed Student’s t-test. Source data are provided as a Source Data file.