Fig. 2

Preparation and characterization of the aPD-L1 NVs. a Establishment of aPD-L1 expressed on MSCs’ membranes by immunofluorescence. Scale bar: 50 µm. b Schematic diagram of aPD-L1 displayed MSC and aPD-L1 NV extraction. cTEM images for aPD-L1 NVs negatively stained with uranyl acetate. Scale bar: 200 nm. d Dynamic diameter of aPD-L1 NVs determined by the dynamic light scattering (DLS). e Schematic diagram of the CO-IP assay principle. f Existence of aPD-L1 on the NVs were examined by Co-IP assay. g CLSM image to show the ability of aPD-L1 NVs to specifically target binding with B16-F10 cells. aPD-L1 NVs were labeled with FITC and nuclei was labeled with DAPI. Scale bar: 50 µm