Fibrinogen-Triggered Matrix Assembly from Designed Peptide-Polymer Conjugates

描述（由申请人提供）：在外科、创伤和应急医学领域，控制出血和粘合受损组织的需要是迫切和重要的临床需要。由于创伤性和多创伤性损伤，失血仍然是第二大最常见的死亡原因（27-39%），其中34%的死亡发生在院前（如门诊）。尽管在开发和部署快速阻止失血的合成系统方面做出了巨大努力，但这些数字仍然存在。天然止血系统（纤维蛋白原/纤维蛋白）虽然在进化上是高度保守的，并且在中度损伤情况下是成功的，但在严重出血创伤和多发创伤的情况下却严重失败，部分原因是大量稀释效应，无法集中关键因素，以及聚合过程中不能产生组织压缩力。在本提案中，我们的目标是将两种使能技术结合起来，1)合理设计的多价纤维蛋白球形肽，其结合凝血因子纤维蛋白原；2)刺激反应微凝胶，将触发组装显示为肿胀水凝胶组装，并探索这些高度新颖的纤维蛋白原（即伤口）触发微凝胶组装的动态范围。我们的中心假设是，显示旋钮肽的刺激反应性微凝胶将经历纤维蛋白原启动的组装进入由微凝胶成分控制的网络。肽密度，链长，交联)和肽(即。亲和和多价)成分。为了验证这一假设，我们将首先量化工程合成纤维蛋白旋钮肽与纤维蛋白原的结合亲和力（Specific Aim 1）。然后，将纤维蛋白旋缩肽偶联到刺激反应微凝胶上，进行微流变学研究，以表征生物合成的混合基质组装（Specific Aim 2）。将我们的旋钮肽（能够“感应”纤维蛋白原和纤维蛋白）与刺激反应性微凝胶（能够通过快速自组装成凝胶基质来“反应”）结合起来，代表了一种高度创新的治疗创伤性出血的方法。这项研究开发的技术的好处是创造了一种止血系统，既能集中凝血因子，又能通过触发肿胀产生压缩力，从而为创伤和多发创伤后需要根治性出血控制的患者服务。

DESCRIPTION (provided by applicant): The need to control bleeding and bind damaged tissues represents a pressing and significant clinical need in the arenas of surgery, trauma, and emergency response medicine. Exsanguination remains the second most prevalent cause of death (27-39%) due to traumatic and polytrauma injury, with 34% of these deaths in the prehospital (e.g. ambulatory) setting. These numbers have persisted despite substantial efforts to develop and deploy synthetic systems that rapidly stem blood loss. The natural hemostatic system (fibrinogen/fibrin), while highly evolutionarily conserved and successful in modest injury situations, critically fails in situations of major hemorrhaging trauma and polytrauma, in part due massive dilution effects, inability to concentrate critical factors, and failure to generate tissue compressive forces during polymerization. In this proposal, our objective is to couple two enabling technologies, i) rationally designed, multivalent fibrin knob peptides, which bind the clotting factor fibrinogen and ii) stimuli-responsive microgels that display triggered assembly into swelling hydrogel assemblies, and to explore the dynamic range of these highly novel fibrinogen (i.e. wound) -triggered microgel assemblies. Our central hypothesis is that stimuli-responsive microgels displaying knob peptides will undergo fibrinogen-initiated assembly into networks that are controlled by the composition of the microgel (ie. peptide density, chain length, crosslinking) and peptide (ie. affinity and multivalency) constituents. To test this hypothesis we will first quantify the binding affinities of engineered synthetic fibrin knob peptides to fibrinogen (Specific Aim 1). Then, following the coupling of said fibrin knob peptides to stimuli-responsive microgels, perform micro-rheological studies to characterize the bio-synthetic hybrid matrix assembly (Specific Aim 2). Coupling our knob peptides, which are capable of "sensing" fibrinogen and fibrin, with stimuli-responsive microgels, which are capable of "responding" via rapid self-assembly into gel matrices, represents a highly innovative approach to hemorrhaging traumatic wounds. The benefit of the technology developed as a consequence of this study is the creation of a hemostatic system that is capable of both concentrating clotting factors and generating compressive forces through triggered swelling, thus serving patients in need of radical hemorrhage control following trauma and polytrauma.