Influence of inhibitors on in vitro proplatelet formation and released EV-PLPs. (A) Representative fields of megakaryocytes extending proplatelet shafts and branching extensions on fibronectin-coated plates. Original magnification ×200. (B) Proplatelet protrusions (PPP) and (C) proplatelet extensions (PPE) were quantitated on day 12 megakaryocytes that had or had not been exposed to the various inhibitors. Mean ± 1 SEM are shown with N = ≥20 cells counted per condition. P values were determined using 1-way ANOVA in comparison with the control. (D) Representative FSC vs SSC for hdPlts (Donor, left), and PLPs harvested from the media from day 12 plates of control and treated megakaryocytes (right 4 graphs). (E) Shows a difference in number of EV-PLPs (from the normal donor Plt FSC/SSC window) obtained from treated megakaryocytes in reference to control ones. (F) Representative FSC vs SSC for hdPlt (Donor, left), and EV-PLPs harvested from the media from day 12 plates of control and treated megakaryocytes (right 4 graphs). The blue indicates CD42b⁺ hdPlts and EV-PLPs among all others released particles. (G) Fold-difference in number of CD41⁺CD42b⁺AnnexinV⁻ (uninjured) EV-PLPs obtained from treated megakaryocytes in reference to control ones. Mean ± 1 SEM are shown with N = 3 independent experiments. P values were determined using 1-way ANOVA in comparison with the control. (H) Percentage of healthy EV-PLPs (as in panel G) compared with the entire EV-PLP population. Mean ± 1 SEM are shown with N = 3 independent experiments. P values were determined using 1-way ANOVA in comparison with the control.