The 19.ek.Fc microspheres coated with a range of 19.ek.Fc surface densities exhibit greater adhesion than matched ek.Fc microspheres in vivo.

The 19.ek.Fc microspheres were prepared using different concentrations of 19.ek.Fc. (A) The number of rolling 19.ek.Fc (black bars) or ek.Fc (white bars) microspheres as a function of concentration of ligand used to coat the microspheres is shown. ANOVA indicated that the number of rolling microspheres was a function of the ligand used to coat the microspheres. Asterisk and pound signs indicate P for individual t tests between 19.ek.Fc microspheres and ek.Fc microspheres prepared with the same concentration of 19.ek.Fc or ek.Fc. *P ≤ .01; #P = .09 for these ttests. (B) The number of firmly adherent 19.ek.Fc (black bars) or ek.Fc (white bars) microspheres as a function of concentration of ligand used to coat the microspheres is shown. ANOVA indicated that the number of firmly adherent microspheres was a function of the ligand used to coat the microspheres. Asterisk and pound signs indicate P for individual t tests between 19.ek.Fc microspheres and ek.Fc microspheres prepared with the same concentration of 19.ek.Fc or ek.Fc. *P < .01; #P = .09 for these ttests. (C) The rolling velocities for individual rolling 19.ek.Fc microspheres were determined. These values were averaged to give the average rolling velocities depicted in panel C. Each bar represents the average of 10 individual 19.ek.Fc microspheres. The average rolling velocity for the leukocytes was about 30 μm/s. ANOVA indicated that the rolling velocity was a function of the concentration of 19.ek.Fc used to coat the microspheres (P < .01). For further details of the surface density of 19.ek.Fc on the microspheres, see the second and third paragraphs of “Discussion” and Table 1. Data from microspheres prepared with 17 and 4 μg/mL of 19.ek.Fc were combined because they appear to have similar surface densities of 19.ek.Fc (Figure 1).