Thermally-Triggered Intra-articular Drug Delivery for OA

在第一个资助周期中，项目2成功地阐明了携带OA的小鼠中OA变化的性质。 关键纤维胶原蛋白的基因突变，包括IX型和Xi型胶原蛋白。如果没有IX型 胶原蛋白，我们了解到关节软骨的完全侵蚀伴随着动物模型的变化而发生。 行为、软骨生物力学和化学。对于项目2，我们将促炎性物质的发现 OA患者血清中的细胞因子，以及我们的OA小鼠模型，并转向开发一种新的细胞因子。 基于向关节递送抗炎化合物的适用于OA的靶向干预。抗炎 减弱IL-1和TNF α活性的药物具有治疗OA的潜力，但需要高 蛋白质剂量并通过静脉或皮下给药时会引起显着的副作用 注射用于炎症性疾病。利用低蛋白剂量并提供持续释放的策略 作为OA的治疗方法，具有很大的临床价值。在项目2中，我们建议开发 并评估原位形成的关节内“药物”贮库“的效用， 用于治疗OA的抗炎蛋白药物的持续递送。我们先前已经 所构建的热响应药物贮库，所述药物为IL-1受体拮抗剂（IL 1 Ra）或可溶性TNF 受体（sTNFRII），与热响应肽缀合。我们已经证明，这些热 由称为ELP的弹性蛋白序列组成的响应肽“标签”， 注射到关节间隙中，这提供了所施用蛋白质的半衰期的25倍增加， 峰值血清暴露减少75%。在目标1中，我们提出研究来评估以下两个方面： ELP-IL 1 Ra和ELP-sTNFRII：（a）针对原代滑膜细胞中的细胞因子的体外生物活性;（B）体内生物活性 递送至大鼠膝关节后的生物分布;（c）体外免疫毒性;和（d）在大鼠中的体内功效。 介导关节内IL-1过表达和/或LPS注射引起的炎性关节疾病 空间在目的2中，我们提出评估ELP-IL 1 Ra和ELP-sTNFRII在一个受试者中的疾病改善作用。 OA的关节不稳定模型，测量如下：（a）大体和组织学关节外观;（B） 滑液和血清生物标志物（通过核心B）;和（c）步态和疼痛感知的参数。我们 假设与这些抗炎药物缀合的热响应ELP将有助于 在关节间隙中的药物半衰期长，同时保留生物活性，减少血清药物暴露， 这些OA临床前模型中的疾病。这个为期5年的项目的结果预计将推动一个 新的药物贮库策略，易于将药物输送到关节，推进疾病修饰的应用 具有显著全身副作用的药物用于治疗OA。

In the first funding cycle, Project 2 was successful in elucidating the nature of OA changes in mice carrying genetic mutations for key fibrillar collagens, including types IX and XI collagen. In the absence of type IX collagen, we learned that complete erosion of joint cartilage occurs with concomitant changes in animal behavior, cartilage biomechanics and chemistry. For Project 2, we take the finding of pro-inflammatory cytokines in the serum of OA patients, as well as our mouse models of OA, and turn towards developing a targeted intervention appropriate for OA based on delivering anti-inflammatory compounds to the joint. Antiinflammatory drugs that attenuate IL-1¿ and TNFa activity have therapeutic potential for OA but require high protein doses and cause significant side effects when administered via intravenous or subcutaneous injection for inflammatory disease. Strategies that utilize low protein doses and provide for sustained release have great potential to achieve value in the clinic as a treatment for OA. In Project 2, we propose to develop and evaluate the utility of an in situ forming, intra-articular 'drug 'depot' that can provide for local and sustained delivery of anti-inflammatory protein drugs for the treatment of OA. We have previously constructed thermally responsive drug depots the drugs, IL-1 receptor antagonist (IL1Ra) or soluble TNF receptor (sTNFRII), conjugated to a thermally responsive peptide. We have shown that these thermally responsive peptide "tags", composed from elastin sequences called ELPs, spontaneously form a depot upon injection into the joint space that provide for a 25-fold increase in the half-life of the administered protein and 75% reduction in peak serum exposure. In Aim 1, we propose studies to evaluate the following for both ELP-IL1Ra and ELP-sTNFRII: (a) in vitro bioactivity against cytokines in primary synoviocytes; (b) in vivo biodistribution following delivery to the rat knee joint; (c) in vitro immunotoxicity; and (d) in vivo efficacy in mediating inflammatory joint disease caused by overexpression of IL-1¿ and/or LPS injection in the joint space. In Aim 2, we propose to evaluate the disease-modifying effects of ELP-IL1 Ra and ELP-sTNFRII in a joint instability model of OA with the following measures: (a) gross and histological joint appearances; (b) synovial fluid and serum biomarkers (through Core B); and (c) parameters of gait and pain perception. We hypothesize that thermally responsive ELPs conjugated to these anti-inflammatory drugs will contribute to long drug half-lives in the joint space while retaining bioactivity, reducing serum drug exposure and modifying disease in these pre-clinical models of OA. The results of this 5-year project are expected to advance a novel drug depot strategy to easily deliver drugs to the joint, advancing the application of disease-modifying drugs with significant systemic side effects for the treatment of OA.