Fig. 5

(A) Analysis of the optimal immobilization rate of Ab_CD24 on mPDA@CuO₂ NRs using ELISA. (B) Analysis of the optimal immobilization rate of Ab_PD−L1 on Ab_CD24-mPDA@CuO₂ NRs using ELISA. (C) Bright-field images of 4T1 cells treated with PBS (Ctrl), mPDA@CuO₂ NRs, Ab_CD24-mPDA@CuO₂ NRs, Ab_PD−L1-mPDA@CuO₂ NRs, and dAb_PD−L1/CD24-mPDA@CuO₂ NRs. The black dots indicate mPDA@CuO₂ NRs. (D) The data are presented as the mean intensity of black dots, which was calculated from the images in (C). The values are expressed as means ± SD (n = 3). Asterisks indicate a significant difference between the mPDA@CuO₂ NRs and Ab_CD24-mPDA@CuO₂ NRs, Ab_PD−L1-mPDA@CuO₂ NRs, dAb_PD−L1/CD24-mPDA@CuO₂ NRs groups (Student’s t-test, *p ≤ 0.05). (E) The effect of residual mPDA@CuO₂ NRs, Ab_CD24-mPDA@CuO₂ NRs, Ab_PD−L1-mPDA@CuO₂ NRs, and dAb_PD−L1/CD24-mPDA@CuO₂ NRs on 4T1 cell viability measured by XTT assay after an additional 24 h of incubation. The values are expressed as means ± SD (n = 3). Asterisks indicate a significant difference between the mPDA@CuO₂ NRs and Ab_CD24-mPDA@CuO₂ NRs, Ab_PD−L1-mPDA@CuO₂ NRs, dAb_PD−L1/CD24-mPDA@CuO₂ NRs groups (Student’s t-test, *p ≤ 0.05)