Figure 7.

Evaluation of prophylactic administration of t-TLNPs in restoring hemostatic efficacy in the tail-clip model in mice with significant bleeding due to the combined effect of platelet depletion and anticoagulation. (A) Schematic of the experimental design where mice were first made thrombocytopenic (TC Mouse) by anti-CD42b dose induced platelet clearance and then further dosed with anticoagulant (Enoxaparin) to induce combine a hemostatic defect (“Defect” mouse). t-TLNP or UNP treatment was administered in the “Defect” mice via an intravenous (retroorbital) route and allowed to circulate for 15 min, and then a tail-clip injury was performed to measure the bleeding time and blood loss. (B) Bleeding time data as a percent of 15 min time period showing that normal mice stopped bleeding in 3.11 ± 0.44 min while the combined effect of thrombocytopenia and anticoagulation in “Defect” mice resulted in continuous bleeding for 15 min (and beyond). Treatment of t-TLNPs in defect mice significantly restores the hemostatic capability, with the mice stopping bleeding in 6.18 ± 3.19 min, while treatment with UNPs has no such effect (mice continue bleeding for 15 min and beyond). (C) Blood loss analysis via a spectrophotometric measurement of hemoglobin in shed blood indicating that the combined effect of thrombocytopenia and anticoagulation in “Defect” mice results in significantly increased blood loss over the 15 min time period in comparison to normal mice. Treatment of “Defect” mice with t-TLNPs significantly reduces blood loss. In contrast, treatment with UNPs did not reduce blood loss but rather exacerbated it, possibly due to a dilution effect. *≤ 0.05, **p≤ 0.01, ***p ≤ 0.001.