In vivo rolling velocity of surface engineering MSCs and selectin expression. (A) Velocity of sLex-modified MSCs and unmodified MSCs on inflamed endothelium within a vessel of 47 μm diameter where the critical velocity (Vcrit) is 191 μm/s. (B) Representative distribution of velocity showing 75% of sLex-MSCs and 25% of unmodified MSCs are below the critical velocity. Cells traveling below the critical velocity decelerate on the vessel wall through receptor/ligand-mediated adhesive interactions. (C) In vivo confocal images of anti–P-selectin–labeled postcapillary venules 24 hours after LPS stimulation. Top: Two venules represent anti–P-selectin–Cy5 labeling in LPS-treated ear and saline-treated ear. Bottom: Two venules represent IgG1, λ-Cy5 labeling in LPS-treated ear and saline-treated ear. Bar represents 500 μm. (D) In vivo confocal images of anti–E-selectin–labeled postcapillary venules 24 hours after LPS stimulation. Top venule represents anti–E-selectin–Cy3 labeling in LPS-treated ear, and bottom venule represents anti–E-selectin–Cy3 labeling in saline-treated ear. Bar represents 500 μm *P < .05.
