In vivo vascular delivery of an MK2 inhibitory peptide for the prevention of smooth muscle cell phenotype switch and intimal hyperplasia.

项目总结 外周动脉疾病(PAD)是一种导致外周动脉阻塞的动脉硬化性疾病， 在美国有超过650万人受到影响。PAD减少血液流动，导致肢体疼痛、无法愈合的伤口，以及 在极端情况下，甚至死亡。经皮腔内血管成形术(PTA)，涉及球囊充气速度 在阻塞部位重新开放动脉腔，是PAD的常见治疗方法。然而，血管壁应力 与球囊扩张(有时结合支架放置)相关的损害和激活 组织中的应激反应，导致再狭窄，动脉再次狭窄。由于这些复杂的情况， 大多数PTA治疗的血管在头12个月内失效。再狭窄是由血管内膜病变过程驱动的 增生(IH)，特征是血管平滑肌细胞(VSMCs)从收缩转变为 合成表型，使它们变得更具迁移性、增殖性和活跃地分泌细胞外 基质(ECM)和炎性细胞因子。合成的VSMC活动产生新的内膜，使其关闭 血管，是晚期动脉粥样硬化甚至血栓形成的沃土。目前的治疗方法 减少高血压的策略仅侧重于通过使用有药物涂层的球囊和 支架。然而，这些方法在临床试验中并未显示出改善血管通畅性的前景。我有过 我一直在寻求抑制p38-MK2“应激反应”信号通路，作为一种更全面的IH 针对驱动病理性VSMC表型转换的潜在机制的治疗。在我最近的文章中 研究，通过使用一种新型的静电络合的多肽(MK2I)抑制MK2 一种pH敏感的形成纳米多聚体的内溶聚合物(MK2I-NPs)被证明在 抑制VSMC增殖、表型转换和IH。在血管搭桥术的背景下，一只兔子 血管移植模型显示，单次术中应用MK2I-NPs(局部到解释)治疗 组织)可抑制术后28天的新生内膜形成，并减轻VSMC表型转换。 移植后急性(7天)应激反应阶段。我们假设在体内，以导管为基础的给药 MK2i联合球囊血管成形术将防止VSMC表型转换和预防 再狭窄和血管衰竭。为了模拟特殊导管的体内释放，我将开发一种体外 并应用该系统评价压力对MK2I渗透和滞留的影响 在血管壁上。此外，我们将使用生物反应器来评估药物动力学和药效学。 MK2i在体外动脉中的表达。最后，基于初始工作中优化的压力条件，我们将应用一种 专门的闭塞灌流导管，在血管的管腔内创建一个“腔”，通过它 在体内，MK2I-NPs可以被控制地用于对流转移到血管壁。这个系统将会 在猪模型中应用以评估体内MK2i对维持VSMC收缩的影响 PTA术后的表型和整体血管通畅率。

PROJECT SUMMARY Peripheral artery disease (PAD), an atherosclerotic disease leading to peripheral artery obstruction, affects over 6.5 million people in the US. PAD reduces blood flow, causing limb pain, non-healing wounds, and in extreme cases even death. Percutaneous transluminal angioplasty (PTA), involving inflation of a balloon at the site of blockage to re-open the arterial lumen, is a common treatment for PAD. However, vascular wall stress associated with balloon distension (sometimes in combination with stent placement) damages and activates stress response in the tissue, leading to restenosis, a re-narrowing of the artery. Because of these complications, most PTA-treated vessels fail within the first 12 months. Restenosis is driven by the pathological process intimal hyperplasia (IH), characterized by vascular smooth muscle cells (VSMCs) switching from a contractile to synthetic phenotype, causing them to become more migratory, proliferative, and active in secreting extracellular matrix (ECM) and inflammatory cytokines. Synthetic VSMC activities produce neointima that closes back off the vessel and that serves as a fertile ground for advanced atherosclerosis or even thrombosis. Current therapeutic strategies to reduce IH focus solely on inhibiting VSMC proliferation through the use of drug coated balloons and stents. However, these methods have not shown promise in improving vessel patency in clinical trials. I have been pursuing inhibition of the p38-MK2 “stress response” signaling pathway as a more comprehensive IH therapy that targets the underlying mechanisms that drive the pathological VSMC phenotype switch. In my recent studies, inhibition of MK2 through the use of a novel peptide therapeutic (MK2i) electrostatically complexed with a pH-sensitive endosomolytic polymer to form nanopolyplexes (MK2i-NPs) proved to be promising in the inhibition of VSMC proliferation, phenotype switching, and IH. In the context of vascular bypass grafts, a rabbit vascular transplant model showed that a single intra-operative treatment with MK2i-NPs (topically to explanted tissue) inhibited neointima formation up to 28 days after surgery and mitigated VSMC phenotype switching during the acute (7 day) stress response phase post-transplant. We hypothesize that in vivo, catheter-based delivery of MK2i in conjunction with balloon angioplasty will prevent VSMC phenotype switching and protect against restenosis and vessel failure. To model in vivo delivery from a specialized catheter, I will develop an ex vivo bioreactor system and apply this system to evaluate the effects of pressure on MK2i penetration and retention in the vessel wall. Additionally, we will use the bioreactor to evaluate pharmacokinetics and pharmacodynamics of MK2i in arteries ex vivo. Finally, based on the pressure conditions optimized in initial work, we will apply a specialized occlusion perfusion catheter to create a “chamber” within the lumen of the vessel through which the MK2i-NPs can be controllably administered for convective transfer into the vascular wall in vivo. This system will be deployed in a pig model to assess the effect of in vivo MK2i delivery on maintenance of VSMC contractile phenotype and overall vessel patency following PTA.