Fig 2: Evaluation of the biological functions of anti‐CD47‐PCM@NP in vivo. A) In vivo and ex vivo targeting ability of anti‐CD47‐PCM@NP and anti‐CD47 in tumor‐bearing mice models determined by live imaging. B) The semiquantitative analysis of the ratio of fluorescence intensity (tumor/liver) of ex vivo imaging. C) In vivo biodistribution of coumarin 6 (C6)‐labeled formulations in tumor‐bearing mice models at (a) 2 h, (b) 4 h, (c) 8 h, and (d) 12 h after i.v. injection of NP/C6, PCM@NP/C6 and anti‐CD47‐PCM@NP/C6. Data are presented as mean ± SD (n = 3) (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; NS represents non‐significance).

Fig 3: Preparation and characterization of anti‐CD47‐PCM@NP. A) Hydrodynamic size and zeta potential of CM vesicles, PLGA cores (NP), PCM@NP, and anti‐CD47‐PCM@NP. Data are means ± SD (n = 3). B) Colocalization of NP/C6 (green) with DiD‐PCM (red), and the colocalization of FITC‐antibody (green) with DiD‐PCM@NP (red), both assessed by confocal laser scanning microscope (CLSM) (scale bar = 5 µm). C) Transmission electron micrographs of (a) NP, (b) CM vesicle, (c) PCM@NP, (d) Anti‐CD47‐PCM@NP, and (e) multiple anti‐CD47‐PCM@NP. All scale bars = 100 nm. D) SDS‐PAGE protein analysis of NP, PCM@NP, CM vesicles, and cancer cell lysate. Samples were tested at equal protein concentrations. CD47 protein and membrane‐specific protein on the cancer cell membrane were efficiently retained on the extracted membrane vesicles and the PCM@NP, detected by western blot. E) Determination of the antibody labeled by PE loaded on the surface of anti‐CD47‐PCM@NP by flow nanoanalyzer. F) The binding affinity of the antibody to the CM vesicles by surface plasmon resonance (SPR).

Fig 4: Anti‐CD47‐PCM@NP effectively distinguished target cells from CD47‐expressing nontarget cells in vitro through indirect active targeting. A) Anti‐CD47‐PCM@NP avoided the blocking of CD47 on RBC and subsequent phagocytosis thus circumvented the on‐target toxicity of free anti‐CD47 towards RBC through the INTACT strategy. Scale bar = 50 µm. B,C) PCM@NP and anti‐CD47‐PCM@NP efficiently escaped the capture by B) macrophages with enhanced and parallel cellular uptake by C) target 4T1 cells, measured by flow cytometry. The antibody selectively dissociated from the carrier PCM@NP at the presence of 4T1 cells with high expression of D) CD47 in contrast to E) CD47−/− 4T1 cells, shown by colocalization images and distribution map of PE‐antibody (red) and PCM@NP/C6 (green). Scale bar = 20 µm (multi‐cell images), 2 µm (single‐cell images). F) The schematic diagram of the microfluidic device. The tumor cells were cultured in the cavity of the microfluidic chip till adherence, and then exposed to flowing anti‐CD47 or anti‐CD47‐PCM@NP, and fluorescent images were captured at predetermined time points. G) Free anti‐CD47 sufficiently bound to the surface of 4T1 cells with high expression of CD47 (a). The antibody dissociated from PCM@NP at the presence of 4T1 cells (b), in contrast with CD47−/− 4T1 group (c) (antibody labeled with FITC, green. PCM@NP labeled with DiD, red). Scale bar = 10 µm. Original movies are shown in Movie S1 (Supporting Information) (a), Movie S2 (Supporting Information) (b), and Movie S3 (Supporting Information) (c), respectively. Data are presented as mean ± SD (n = 3). (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; NS represents non‐significance).

Fig 5: Antitumor efficacy of anti‐CD47‐PCM@NP and mechanistic investigation by CyTOF analysis. A) Representative images and phagocytic index of C57BL/6 bone marrow‐derived macrophages (BMDM) phagocytosing tumor cells following treatment with PCM@NP, anti‐CD47, and anti‐CD47‐PCM@NP. Scale bar = 50 µm. B) Timeline of the anti‐tumor efficacy study on tumor‐bearing mice (red arrows indicate intravenous administrations), and average tumor growth curves and picture of tumor tissues after the treatment. C) Individual tumor growth curves in each group. D) viSNE plot of intratumoral cells in tumor tissues after treatment with saline, PCM@NP, anti‐CD47, anti‐CD47‐PCM@NP and all groups merged. E) Heat map of the surface molecule and functional molecule expression of different subsets of immune cells in tumor tissues from all groups merged. F) tSNE visualization of all samples with the expression of CD4 and CD8a respectively. G) Percentage of cells in each cluster after treatment from each group. Data represented as mean ± SD (n = 6). (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; NS represents nonsignificance).