Fig. 5.

α-E-LEAPs exhibit selective adhesion to TNF-α inflamed endothelium in vivo. Mice were given an intrascrotal injection of TNF-α or no injection. Approximately 2 h later, α-E-LEAPs or rat IgG PLA–PEG particles (negative control) were injected into the mice (5 × 10⁶ per mouse), and the number of adherent particles was observed in the postcapillary venules of the cremaster muscle. A significantly greater number of α-E-LEAPs were adherent in TNF-α-pretreated mice compared to control mice, and a significantly greater number of α-E-LEAPs were adherent in TNF-α-pretreated mice compared to rat IgG PLA–PEG particles. All adherent particles were firmly adherent (i.e., not rolling). Ligand indicates which molecule was coupled to the PLA–PEG particles, a mAb to murine E-selectin (α-E) or rat IgG (IgG); TNF-α indicates pretreatment of mice with TNF-α 2 h before the experiment (+) or no pretreatment (-); *, P < 0.05 compared to right bars. FACS revealed that the α-E-mAb can be conjugated to PLA–PEG particles (data not shown).