Targeted homing of surface engineering MSCs to inflamed tissue. (A) Percentage increase in sLe^x-modified MSCs compared with unmodified MSCs that homed to the inflamed and saline ear (noninflamed) 24 hours after systemic infusion. The average number of sLe^x-modified MSCs (per field of view) that homed to the inflamed ear was 48 compared with 31 unmodified MSCs, whereas the average number of sLe^x-modified MSCs (per field of view) that homed to the saline ear (noninflamed) was 31 compared with 29 unmodified MSCs. (B) Representative image of MSC localization in the inflamed ear at 24 hours after injection of DiD-labeled sLe^x-MSCs (red) and DiR-labeled unmodified MSCs (green). Most cells extravasated though the vessel walls (visualized by FITC-dextran, blue). No differences in extravasation efficiency were observed, thus indicating that the enhanced homing was because of an engineered rolling response through MSC surface functionalization with sLe^x *P < .05.