FIG. 5.

Analysis of collected platelets. (A) Flow cytometry analysis of collected platelets in the microtube flow effluent: (ii) microtubes coated with SDF-1α and a combination of Matrigel, FBG, and vWF, (iii) uncoated microtubes, and (iv) microtubes coated with SDF-1α and type I collagen. Collected platelets were analyzed as CD41⁺ events with the same physical parameters and fluorescence intensity of human blood platelets (i). (B) To exclude fragments, collected cells were double-stained with an anti-CD41 antibody and calcein-AM. A representative dot plot is shown. (C) Circumferential microtubule coils were observed with an anti-tubulin antibody in the majority of collected platelets (ii) when compared to human peripheral blood platelets (i). (D, E) Platelets collected after bioreactor perfusion (Dii, Eii) revealed increased exposure of P-selectin to the plasma membrane and increased PAC-1 binding after thrombin stimulation, as in human peripheral blood platelets (Di, Ei) (gray line indicates unstimulated platelets; black line, thrombin-stimulated platelets). (F) Spreading of collected platelets after perfusion (ii) was analyzed by SEM in adhesion to type I collagen and compared to human peripheral blood platelets (i). Color images available online at www.liebertonline.com/tec