BMNCs bind to immobilized fucoidan through L-selectin and αMβ2. (A) Dose-response binding. CFSE-labeled BMNCs were allowed to bind to hydrazide-coated wells that had been precoated with various concentrations of fucoidan (•), desulfated-fucoidan (D-Fuc; □), or heparin (▴). The wells were then washed and cells were lysed. Fluorescence was measured and the number of bound BMNCs was calculated. (B) Binding specificity of fucoidan. CFSE-labeled BMNCs were allowed to bind to plates coated with fucoidan in the presence of EDTA or sugars (fucoidan, mannan, heparin, glucose, or fucose); *P ≤ .009 compared with the control (Nil) group. (C) Progenitor binding to fucoidan. BMNCs preincubated with fucoidan (N-Fuc) or media (Nil) were allowed to bind BSA (▨) or immobilized fucoidan. Bound CFU-Cs were scored in methylcellulose cultures. *P < .05 compared with BSA and N-Fuc. Binding in the untreated group (Nil) corresponds to 29% ± 2% of the input CFU-Cs. (D) BMNCs binding to immobilized fucoidan are mediated by L-selectin and the αMβ2 integrin. CFSE-labeled BMNCs were allowed to bind to fucoidan-coated plates in the presence of antirat IgG control, anti–L-selectin antibody (MEL14), anti-αM antibody (M1/70), or in the presence of both function-blocking antibodies. In all panels, error bars represent mean ± SEM bound cells/mm2. *P < .05; **P ≤ .01 compared with vehicle (Nil) or control IgG groups.