Sustained Release Relaxin-2 for the Treatment of Frozen Shoulder

项目概要/摘要 该提案描述了肩关节纤维化（也称为冷冻疗法）的创新和恢复性治疗 肩膀。在美国 1500 万患有肩关节纤维化的人中，超过 1.6 每年有数百万人寻求医疗服务。目前的治疗选择，包括关节内皮质类固醇注射， 非甾体类抗炎药 (NSAID) 和神经阻滞剂只能提供有限和暂时的缓解 只关注患者症状，但没有解决疾病的根本原因——纤维化的积累 胶原组织。物理治疗是主要的治疗选择，但时间较长且效果不佳。外科 在严重的情况下会使用干预措施，但这些程序充满了并发症，并且可能进一步 加剧纤维化。我们建议使用人松弛素 2 (RLX) 作为治疗以下疾病的新型疗法： 肩关节纤维化。 RLX 是一种内源性 6-kDa 肽激素，主要有助于软化皮肤 分娩前通过细胞外基质重塑耻骨联合和骨盆韧带。重新利用这个 用于治疗关节纤维化的抗纤维化肽代表了针对该疾病的首个蛋白质疗法。 具体来说，我们描述了 RLX 在关节空间中的详细作用机制研究，并结合 从新型和成熟制备的微粒中封装和持续递送 RLX 生物相容性和可生物降解的聚合物。拟议的实验将定义分子和 关节间隙中 RLX 信号传导的结构基础，并将使用体内肩关节挛缩 固定模型检验 RLX 通过抑制 TGF-β1 减少关节纤维化的假设 通过 NO-sGC-cGMP 途径发出信号，从而降低关节僵硬并增加肩部压力 运动范围（ROM）。此外，我们假设 RLX 从单个关节内持续释放 注射负载 RLX 的聚合物微粒将减轻关节纤维化的症状和原因。 重要的是，初步数据支持拟议的研究、充分表征的材料和严格的研究 实验设计已经建立，重要的跨学科合作和专业知识已经到位 来解决假设。该五年提案的具体目标如下。目标 1 定义了 RLX 与其受体 RXFP1 结合的分子机制，为基于结构的 RLX的优化。目标 2 确定了负载 RLX 的可生物降解和 生物相容性聚合物微粒，包括 RLX 释放动力学和颗粒降解。目标 3 评估 目标 2 中确定的最佳 RLX 负载微粒制剂的药代动力学和功效 建立的体内肩部挛缩模型。

PROJECT SUMMARY/ABSTRACT This proposal describes an innovative and restorative treatment for shoulder arthrofibrosis, also known as frozen shoulder. Of the 15 million individuals in the United States suffering from shoulder arthrofibrosis, more than 1.6 million seek medical care each year. Current treatment options, including intraarticular corticosteroid injections, non-steroidal anti-inflammatory drugs (NSAIDs), and nerve blockers, provide only marginal and temporary relief of patient symptoms and do not address the underlying cause of the disease – the accumulation of fibrotic collagenous tissue. Physical therapy is a main treatment option but it is prolonged and suboptimal. Surgical interventions are used in severe cases, but these procedures are fraught with complications and can further aggravate the fibrosis. We propose the use of human relaxin-2 (RLX) as a novel therapeutic for the treatment of shoulder arthrofibrosis. RLX is an endogenous 6-kDa peptide hormone that primarily aids in softening of the pubic symphysis and pelvic ligaments prior to childbirth via extracellular matrix remodeling. Repurposing this antifibrotic peptide to treat arthrofibrosis represents a first-of-its-kind protein therapy for this disease. Specifically, we describe detailed mechanism-of-action studies for RLX in the joint space combined with encapsulation and sustained delivery of RLX from microparticles prepared from both novel and well-established biocompatible and biodegradable polymers. The proposed experiments will define the molecular and structural basis for RLX signaling in the joint space and will use an in vivo shoulder joint contracture immobilization model to test the hypothesis that RLX reduces arthrofibrosis by inhibiting TGF-β1 signaling via the NO-sGC-cGMP pathway, thereby decreasing joint stiffness and increasing shoulder range of motion (ROM). Further, we hypothesize that sustained release of RLX from a single intraarticular injection of RLX-loaded polymeric microparticles will alleviate both the symptoms and causes of arthrofibrosis. Importantly, preliminary data support the proposed studies, well-characterized materials and rigorous experimental designs are established, and essential cross-disciplinary collaborations and expertise are in place to address the hypotheses. The specific aims of this five-year proposal are as follows. Aim 1 defines the molecular mechanism of by which RLX binds its receptor, RXFP1, providing a framework for structure-based optimization of RLX. Aim 2 determines the material property characteristics of RLX-loaded biodegradable and biocompatible polymeric microparticles, including RLX release kinetics and particle degradation. Aim 3 assesses the pharmacokinetics and efficacy of the optimal RLX-loaded microparticle formulation identified in Aim 2 using an established in vivo shoulder contracture model.