D′D3-Fc is retained in the circulation and elevates FVIII plasma levels for >7 days in Vwf^−/− mice. VWF fragment levels (normalized to the value at 5 minutes as 100% [%5min], A) and FVIII levels (B) were followed in Vwf^−/− mice (n = 4-5) transfused with 200 μL pooled PPP derived from hydrodynamically injected Vwf^−/− mice (n = 5-7). Donor PPP composition (VWF in nM of subunit, FVIII in %C57BL/6J): D′D3-Fc (9.5 nM, 41.8%), D′D3 (4.9 nM, 67.2%), and wtVWF (49.7 nM, 108.6%). (A) VWF levels for wtVWF and D′D3 shown here are from a subset of mice included in Figure 3 whose FVIII levels were also measured. (B) FVIII levels are expressed as %C57BL/6J, where 100% is defined as the amount of FVIII in PPP pooled from 10 C57BL/6J mice. The mean pretransfusion FVIII levels from all treated Vwf^−/− mice (n = 14) are indicated by the black line (8.5%). Data (mean ± SD) were nonlinearly regressed (curves).