Influence of HA and CV on M1 polarization of macrophages and antitumor potential of EVs in 4T1 cells. (A) Cell viability of RAW 264.7 cells treated with HA, CV, or a combination of both. (B) Analysis of M1 (by means of CD68 expression) and M2 polarization (by means of CD163 expression) of RAW cells in response to IL-4. LPS + IFNγ, RAW-EVs, and M1-EVs alone and combined with HA, CV, or both. (C) Western blot analysis of E-cadherin and vimentin levels in 4T1 cells in response to EVs (left) and relative exposure (right). (D) Cell viability of 4T1 cells in response to RAW, M1, and MM1-EVs. (E) Cell viability of 4T1 cells in response to M1 and MM1-EVs loaded with DOX and free DOX. (F) Annexin V-FITC/DAPI double staining to evaluate apoptosis induction in 4T1 cells in response to free DOX and DOX-loaded M1 and MM1-EVs. Data are means ± SEM (n = 3). Non-significant (ns); **** p < 0.0001; *** p < 0.001; ** p < 0.01; * p < 0.05.