There is a lack of prehospital hemostatic agents, especially for noncompressible hemorrhage. We previously reported PolySTAT, a unimeric, injectable hemostatic agent, that physically cross-links fibrin to strengthen clots. In this work, we sought to improve the water-solubility and synthesis yield of PolySTAT to increase the likelihood of clinical translation, reduce cost, and facilitate future mass production. First, we focused on side-chain engineering of the carrier polymer backbone to improve water-solubility. We found that substitution of the 2-hydroxyethyl methacrylate (HEMA) monomer with glycerol monomethacrylate (GmMA) significantly improved the water-solubility of PolySTAT without compromising efficacy. Both materials increased clot firmness and decreased lysis as measured by rotational thromboelastometry (ROTEM). Additionally, we confirmed the in vivo activity of GmMA-based PolySTAT by improving rat survival in a femoral artery bleed model. Second, to reduce waste, we evaluated PolySTAT synthesis via direct polymerization of peptide monomers. Methacrylamide and methacrylate peptide-monomers were synthesized and polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. This approach markedly improved the yield of PolySTAT synthesis while maintaining its biological activity in ROTEM. This work demonstrates the flexibility of PolySTAT to a variety of comonomers and synthetic routes and establishes direct RAFT polymerization of peptide monomers as a potential route of mass production.

中文翻译：

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优化注射用止血剂PolySTAT的高分子化学和合成方法

缺乏院前止血剂，尤其是对于不可压缩的出血。我们之前曾报道过PolySTAT，一种可注射的单种止血剂，可物理地交联血纤蛋白以增强血凝块。在这项工作中，我们试图提高PolySTAT的水溶性和合成产率，以增加临床翻译的可能性，降低成本并促进未来的批量生产。首先，我们专注于载体聚合物主链的侧链工程设计，以提高水溶性。我们发现用甲基丙烯酸单甘油酯（GmMA）取代甲基丙烯酸2-羟乙酯（HEMA）单体可显着提高PolySTAT的水溶性，而不会影响功效。通过旋转血栓弹力测定法（ROTEM）测得，两种材料均能增加凝块硬度并减少裂解。另外，GmMA的PolySTAT的体内活性通过改善股动脉出血模型中的大鼠存活率来实现。其次，为了减少浪费，我们通过肽单体的直接聚合评估了PolySTAT的合成。通过可逆的加成-断裂链转移（RAFT）聚合反应合成并聚合了甲基丙烯酰胺和甲基丙烯酸酯单体。这种方法显着提高了PolySTAT合成的产量，同时在ROTEM中保持其生物学活性。这项工作证明了PolySTAT对多种共聚单体和合成路线的灵活性，并建立了直接的RAFT聚合单体的肽单体作为潜在的大规模生产途径。