Chemical activity of ODSH. (A) Chemical structure of the ODSH polysaccharide showing replacement of 2 sulfhydryl groups with hydroxyl groups at the 2-O and 3-O positions. (B) ELISA performed with an LRP1-coated plate showing dose-dependent inhibition of PF4 binding with increasing ODSH concentrations. (C) Uptake of PF4 by cultured megakaryocytes. N = 3 experiments performed in duplicate. P < .001 for PF4 vs PF4+ODSH for WT murine megakaryocytes, and P = .002 for PF4 vs PF4+ODSH for Cxcl4^−/− murine megakaryocytes.