Cell surface engineered MSCs display enhanced rolling intactions in vitro. (A) Conjugation of sLe^x on the surface of the MSCs through covalent biotinylation and a streptavidin-biotin bridge. (B) Velocity of sLe^x-modified cells compared with PBS-treated cells and glucose-modified cells at 0.36 dyne/cm² on P-selectin–coated substrates. (C) Number of interacting sLe^x-modified cells compared with PBS-treated cells and glucose-modified cells per unit area at 0.36 dyne/cm² on P-selectin–coated substrate over 10 seconds with 0.45 mm² area. (D) Velocity of sLe^x-modified MSCs, HL60, and free stream velocity (theoretically calculated from flow chamber geometry and fluid flow rate) at increasing shear stress.