Thermally-Triggered Intra-articular Drug Delivery for OA

在第一个资助周期中，项目2成功地阐明了携带骨质疏松症的小鼠的骨性关节炎变化的性质 关键纤维胶原的基因突变，包括IX型和XI型胶原。在没有类型IX的情况下 胶原蛋白，我们了解到关节软骨的完全侵蚀会伴随着动物的变化 行为，软骨生物力学和化学。对于项目2，我们将促炎的发现 OA患者血清中的细胞因子，以及我们的OA小鼠模型，并转向发展成一种 在向关节输送抗炎化合物的基础上，对骨关节炎进行适当的靶向干预。抗炎 降低IL-1和TNFa活性的药物对骨性关节炎有治疗潜力，但需要很高的 蛋白质剂量，经静脉或皮下给药时会引起显著副作用 治疗炎症性疾病的注射剂。利用低蛋白质剂量并提供持续释放的策略 作为一种治疗骨性关节炎的药物，具有很大的临床应用价值。在项目2中，我们建议开发 并评估原位形成的、关节内的“药库”的用途，该“药库”可提供局部和 抗炎蛋白药物持续给药治疗骨性关节炎。我们之前已经 构建温度响应性药物仓库，药物为IL-1受体拮抗剂(IL1ra)或可溶性肿瘤坏死因子 受体(STNFRII)，与热反应多肽结合。我们已经证明了这些在热学上 由称为ELP的弹性蛋白序列组成的响应性多肽“标签”会自发地形成一个储存库 注射到关节间隙，使给药蛋白质的半衰期增加25倍， 血清暴露峰值降低75%。在目标1中，我们建议对以下两种情况进行评估 ELP-IL1Ra和ELP-sTNFRII：(A)原代滑膜细胞对细胞因子的体外生物活性；(B)体内 大鼠膝关节注射后的生物分布；(C)体外免疫毒性； IL-1和/或内毒素在关节内过表达所致炎症性关节病的介导性研究 太空。在目标2中，我们建议评估ELP-IL1Ra和ELP-sTNFRII对小鼠的疾病修饰作用。 关节不稳定模型及下列措施：(A)大体和组织学关节表现；(B) 关节液和血清生物标志物(通过Core B)；以及(C)步态和痛觉参数。我们 假设与这些抗炎药物结合的体温敏感型ELP将有助于 药物在关节腔内半衰期长，同时保持生物活性，减少血清药物暴露和修饰 这些临床前的骨性关节炎模型中的疾病。这一为期5年的项目的成果预计将提前一年 新的药库战略，轻松将药物输送到关节，推进疾病修饰的应用 治疗骨性关节炎有显著全身副作用的药物。

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.