Department of Pharmacodynamics, Medical University of Bialystok, Mickiewicza 2c, 15-089 Bialystok, Poland.
Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji 671-2280, Japan.
Int J Mol Sci. 2021 Oct 15;22(20):11149. doi: 10.3390/ijms222011149.
Uncontrolled bleeding after enoxaparin (ENX) is rare but may be life-threatening. The only registered antidote for ENX, protamine sulfate (PS), has 60% efficacy and can cause severe adverse side effects. We developed a diblock copolymer, heparin-binding copolymer (HBC), that reverses intravenously administered heparins. Here, we focused on the HBC inhibitory activity against subcutaneously administered ENX in healthy mice. BALB/c mice were subcutaneously injected with ENX at the dose of 5 mg/kg. After 110 min, vehicle, HBC (6.25 and 12.5 mg/kg), or PS (5 and 10 mg/kg) were administered into the tail vein. The blood was collected after 3, 10, 60, 120, 360, and 600 min after vehicle, HBC, or PS administration. The activities of antifactors Xa and IIa and biochemical parameters were measured. The main organs were collected for histological analysis. HBC at the lower dose reversed the effect of ENX on antifactor Xa activity for 10 min after antidote administration, whereas at the higher dose, HBC reversed the effect on antifactor Xa activity throughout the course of the experiment. Both doses of HBC completely reversed the effect of ENX on antifactor IIa activity. PS did not reverse antifactor Xa activity and partially reversed antifactor IIa activity. HBC modulated biochemical parameters. Histopathological analysis showed changes in the liver, lungs, and spleen of mice treated with HBC and in the lungs and heart of mice treated with PS. HBC administered in an appropriate dose might be an efficient substitute for PS to reverse significantly increased anticoagulant activity that may be connected with major bleeding in patients receiving ENX subcutaneously.
依诺肝素（ENX）给药后出现无法控制的出血较为罕见，但可能危及生命。依诺肝素唯一注册的解毒剂硫酸鱼精蛋白（PS）的疗效为 60%，并可能引起严重的不良反应。我们开发了一种嵌段共聚物，肝素结合嵌段共聚物（HBC），可逆转静脉内给予的肝素。在这里，我们专注于 HBC 对健康小鼠皮下给予 ENX 的抑制活性。BALB/c 小鼠以 5mg/kg 的剂量皮下注射 ENX。给药后 110min，尾静脉给予载体、HBC（6.25 和 12.5mg/kg）或 PS（5 和 10mg/kg）。给药后 3、10、60、120、360 和 600min 收集血液。测量抗因子 Xa 和 IIa 的活性和生化参数。收集主要器官进行组织学分析。HBC 低剂量给药后 10min 可逆转 ENX 对抗因子 Xa 活性的作用，而高剂量时，HBC 可在整个实验过程中逆转抗因子 Xa 活性。两种剂量的 HBC 均可完全逆转 ENX 对抗因子 IIa 活性的作用。PS 未逆转抗因子 Xa 活性，仅部分逆转抗因子 IIa 活性。HBC 调节生化参数。组织病理学分析显示，HBC 处理的小鼠肝脏、肺脏和脾脏以及 PS 处理的小鼠肺脏和心脏发生变化。给予适当剂量的 HBC 可能是 PS 的有效替代品，可逆转与接受皮下 ENX 治疗的患者大出血相关的抗凝活性显著增加。
