Fig 1: Characterisation of aPDL1-conjugated platelets and disruption of tumour blood vessel caused by Vadimezan.a Schematic of using aPDL1-engineered platelets combined with Vadimezan to treat tumour metastases. b Confocal images of aPDL1-conjugated platelets (P@aPDL1). Platelets were labelled with WGA-488 (green) and the aPDL1 was tracked by Cy5-conjugated anti-rat IgG antibody (red), scale bar: 5 μm. c Flow cytometry analysis of the proteins on the native platelets and P@aPDL1. CD154 and CD62P were measured after the activation of the platelet. d Collagen-binding ability of native platelet and P@aPDL1. The blank was not pretreated with collagen, scale bar: 200 μm. e TEM image of the P@aPDL1 and platelet-derived microparticles (PMPs) generated by stimulation of P@aPDL1 with thrombin, scale bar: 500 nm. f The photograph and H&E staining image of the 4T1 tumour post-treatment with PBS and Vadimezan. Black arrows marked the haemorrhaging sites in the tumour, scale bar: 20 µm. g Confocal images of the blood vessels and activated platelets in the 4T1 tumours treated with Vadimezan. Blood vessels were marked with an anti-CD31 antibody (red), the activated platelets were labelled with anti-CD62P antibody (green), and the nucleus were stained with Hoechst 33342 (blue), scale bar: 100 µm.