sLexglycomimetics alter rolling to arrest on E-selectin and bond mechanics. (A) PMNs rolling to arrest over E/I substrates (<0.4 μm/sec) treated with vehicle (PBS), Rivipansel, or GSnP-6 was measured and normalized to total number of interacting PMNs; data are reported as mean ± SEM (n = 3 separate experiments; *P < .05; ***P < .001 compared with vehicle). (B) PMN rolling velocity was quantified over an E-selectin substrate treated with vehicle, Rivipansel (6.5 μM), or GSnP-6 (12 μM) and binned at intervals of 0.4 μm/sec. Comparison of GMI-1070 showed *significance and GSnP-6 showed ***significance over untreated controls (n = 3 separate experiments; *P < .05 and ***P < .001). (C) Schematic depicts dynamic interaction between PMNs and recombinant E-selectin-coated protein-G beads recorded at 50 frames per second in the flow channel. Isolated human PMNs were treated with an anti-Mac-1 and anti-PSGL-1 blocking antibodies and then perfused through flow chambers. PMNs pivot over beads and pull a membrane tether at defined wall shear stress. Adhesive interactions were identified as collisions that had a visible pause in PMN motion for at least 1 frame, along with velocities below the hydrodynamic velocity. (D) Tether duration was compared with step-wise increases in calculated tether forces. (E) Tether efficiency (collisions resulting in adhesion divided by the total collisions observed) as shear stress was ramped in a stepwise manner. Data were reported as mean ± SEM (n = 3 separate experiments; **P < .01; *P < .05 glycomimetics compared with 9 pN tether force and 0.25 dynes/cm2 wall shear stress).
