The effect of anionic polysaccharides on SS RBC adhesion to HUVEC. RBC suspensions were untreated (None, n = 10) or treated with 200 μg/mL of the indicated anionic polysaccharide for 30 minutes before being perfused through an endothelialized flow chamber at 1 dyne/cm². Adherent RBC per mm² were counted and reported as percent adhesion as compared with the control values that were normalized to 100%. Percent adhesion is depicted as the mean ± SD. CSA (n = 6) (40% inhibition, *P < .001), HDS (n = 9) (78% inhibition, *P < .0001), and LDS (n = 7) (52% inhibition, *P < .0001) were most effective in inhibiting adhesion. Heparin (n = 6) (26% inhibition, P < .002) was mildly effective, whereas CSB (n = 6), CSC (n = 4), HS (n = 3), and FUC (n = 7) were not effective inhibitors (pairedt-test).