Collagen-mediated approaches to improve the local delivery and hypothermic release of osteoarthritis therapeutics

项目摘要 创伤后骨关节炎（PTOA）是关节损伤的潜在后果，约50%的膝关节炎患者 受伤后10年内出现PTOA。目前，不存在PTOA的治愈方法，但是PTOA的急性性质 促发性损伤为PTOA治疗提供了一种独特的方法：靶向预防性药物 干预以减轻/预防损伤后疾病的发生。许多临床前研究针对 治疗已经进行。然而，由于关节内（i.a.）药物清除，疾病- 改变药物效率是非常有限的，需要重复给予高剂量的游离药物以获得功效。 给内务部的低效率。游离药物的给药，延长药物停留时间的递送方法 通过靶向受伤关节的组织， 功效我们提出了一种新颖的和通用的平台，用于热响应，局部递送候选物。 PTOA药物用于损伤关节，以限制PTOA的开始/进展。我们的方法依赖于我们的开拓性 弹性蛋白-胶原蛋白-肽缀合物的开发， 体温下长期被动释放和轻度低温下加速/爆发释放 温度此外，构成囊泡外部“壳”的胶原蛋白样肽可以靶向变性的胶原蛋白。 胶原蛋白，允许在具有升高的胶原蛋白损伤/重塑的组织中积累。 在本提案中，我们将评估候选PTOA疾病修饰药物的载量（重点是 地塞米松（Dex）），并监测其稳定性，以及 被动和低温触发的药物释放。对幼稚和“损伤/活化”软骨细胞的研究， 滑膜成纤维细胞和单核细胞/巨噬细胞以及关节软骨和滑膜组织外植体将 确认细胞/生物相容性，并量化载Dex的ECNV对“损伤”标志物的抑制。我们 将使用PTOA的非侵入性重复关节负荷（过度使用）模型进行体内实验， 证明了在关节内（i.a.）注射多尺度 将采用体内、原位和组织学/免疫组织化学分析来评价 被动和低温触发的货物释放的药代动力学，组织定位/生物分布， 以及递送到健康和早期PTOA关节的ECNV的局部和全身生物相容性/安全性。 最后，我们将描述基于ECNV的Dex递送改善疾病修饰生理学的能力。 和PTOA结果在上述非侵入性关节损伤模型中具有显著性，其中标准i. a. 脂质体和游离Dex治疗作为对照。虽然这项工作的重点是增加 PTOA治疗效果的研究，也将为使用胶原靶向ECnV药物载体奠定基础 广泛的以异常胶原蛋白重塑为特征的疾病和病理。

PROJECT SUMMARY Post-traumatic osteoarthritis (PTOA) is an insidious consequence of joint injury, ~50% of patients with knee- injuries exhibit PTOA within 10-years of injury. Presently, no cure for PTOA exists, but the acute nature of the precipitating injuries provides for a unique approach to PTOA treatment: targeted prophylactic pharmaceutical intervention to mitigate/prevent the initiation of disease post-injury. Many pre-clinical investigations for targeted treatment have been conducted. However, due to incredibly rapid intra-articular (i.a.) drug clearance, disease- modifying drug efficiency is highly limited, requiring repeated high-dose administration of free drug for efficacy. Give the inefficiencies of i.a. administration of free drug, delivery approaches that extend drug-residence time by targeting the tissues of the injured joint could represent a cost-effective method of increasing therapeutic efficacy. We propose a novel and versatile platform for the thermally responsive, localized delivery of candidate PTOA drugs to injured joints to limit initiation/progression of PTOA. Our approach relies on our pioneering development of elastin-collagen-peptide conjugates that uniquely form cargo-laden nanovesicles that facilitate long-term passive release at body temperature and accelerated-/burst-delivery at mildly hypothermic temperatures. In addition, the collagen-like peptides comprising the vesicle’s outer ‘shell’ can target denatured collagens, allowing accumulation in tissues with elevated collagen damage/remodeling. In this proposal, we will evaluate the loading of candidate PTOA disease-modifying drugs (with a focus on dexamethasone (Dex)) in refined elastin-collagen nano-vesicles (ECnV) and monitor their stability, as well as passive and hypothermally-triggered drug release. Studies on naïve and ‘injured/activated’ chondrocytes, synovial fibroblasts, and monocyte/macrophages, and articular cartilage and synovial tissue explants, will confirm the cyto-/biocompatibility and quantify the suppression of ‘injury’ markers by Dex-loaded ECnVs. We will conduct in vivo experiments using a non-invasive repeated joint loading (overuse) model of PTOA to demonstrate the selective retention of ECnVs within injured joints after intra-articular (i.a.) injection. Multi-scale in vivo, in situ, and histological/immunohistochemical analyses will be employed to evaluate the pharmacokinetics of passively and hypothermally-triggered cargo release, tissue localization/biodistribution, and the local and systemic biocompatibility/safety of ECnVs delivered to both healthy and early-PTOA joints. Finally, we will characterize the ability of ECnV-based delivery of Dex to improve disease-modifying physiology and PTOA outcomes prophylactically in the aforementioned non-invasive, joint injury model, with standard i.a. liposomal and free-Dex treatments serving as comparators. Although the proposed work focuses on increasing PTOA therapy effectiveness, it will also lay a foundation for the use of collagen-targeting ECnV drug carriers across a broad range of diseases and pathologies characterized by aberrant collagen remodeling.