Sustained Delivery of RhoA activator for Treatment of Intervertebral Disc Degeneration

椎间盘源性背痛是导致残疾的主要原因，涉及椎间盘退行性改变 椎间盘（IVD）。由于只有一小部分患者对传统疗法有良好反应 治疗只能解决症状而不是疾病，因此需要新的疗法 治疗椎间盘退变（DD）。 IVD 的无血管性质和致密基质使其 全身给药的药物到达细胞核内的靶细胞具有挑战性 髓（NP）。虽然局部椎间盘内直接注射治疗药物到 NP 中是一种 临床相关的递送方法，其持久性低且从体内快速扩散 注射部位会导致短暂的益处、脱靶效应和潜在的全身毒性。在 根据目前的提案，我们将开发一种基于电荷（亲和素）的纳米载体系统，以提供 长达数月的大分子量药物（CN03）椎间盘内注射至大鼠体内体外诊断 单一管理，减少了经常观察到的低渗透率或短期效益 IVD 中的疾病缓解药物。 CN03 是一种 RhoA GTP 酶激活剂。我们最近发现 由肌动球蛋白收缩性的 Rho GTPase 调节介导。我们的研究表明 RhoA 可以调节主促炎转录因子 NF-ĸB 及其下游 信号传导包括基质水平的降解作用，使得 Rho GTPase 介导 肌动球蛋白收缩性是预防促炎细胞因子诱导的新治疗靶点 IVD ECM 的降解。该 MPI 提案的目标是测试 CN03 作为 IVD 变性临床前模型中的新型治疗药物，并设计持续的 CN03 受控局部给药的输送系统。在目标 1 中，我们将量化肌动球蛋白 CN03 在大鼠 IVD 穿刺损伤模型中的收缩性和生物学功效。在目标 2 中，我们将 合成并表征了用于大鼠 IVD 中持续释放 CN03 的 NP 内药物库 为期1个月。在目标 3 中，我们将评估 CN03 缀合的治疗效果 亲和素-葡聚糖在体内大鼠 IVD 穿刺损伤模型中的作用。顺利完成这些高 风险/高回报研究将证明肌动球蛋白收缩性是一种合适的疾病 修改 DD 的药物靶点，亲和素阳离子纳米结构可以持续输送 大分子量蛋白质在 IVD 中的有效期长达 1 个月，并且优化了 CN03 的递送 结合的亲和素-右旋糖酐可改善体内椎间盘功能修复。这些治疗策略 具有高度转化性，因此未来的研究将在大型动物中评估这些策略 DD 模型和治疗症状性背痛。

Discogenic back pain, is a leading cause of disability, and involves degenerative changes of the intervertebral disc (IVD). Since only a small subset of patients responds favorably to conventional treatments which address the symptoms but not the disease, there is a need for new therapies to treat disc degeneration (DD). The avascular nature and the dense matrix of the IVD makes it challenging for systemically administered drugs to reach their target cells inside the nucleus pulposus (NP). While local intra-discal injection of therapeutic drugs directly into the NP is a clinically relevant delivery approach, it suffers from low persistence and rapid diffusion from the injection site resulting in short lived benefits, off target effects and potentially, systemic toxicity. In the current proposal, we will develop a charge based (Avidin) nanocarrier system to deliver a months long dose of a large molecular weight drug (CN03) intradiscally to the rat IVD in vivo from a single administration, reducing the often-observed low penetration or short-lived benefits of disease modifying drugs in the IVD. CN03 is a RhoA GTPase activator. We recently discovered are mediated by Rho GTPase regulation of actomyosin contractility. Our study demonstrates that RhoA can regulate the master pro-inflammatory transcription factor NF-ĸB, its downstream signaling including degradative effects at the matrix level, making Rho GTPase mediated actomyosin contractility a novel therapeutic target to prevent pro-inflammatory cytokine induced degradation of the IVD ECM. The goal of this MPI proposal is to test the efficacy of CN03 as a novel therapeutic drug in a preclinical model of IVD degeneration and to design a sustained delivery system for controlled local administration of CN03. In Aim 1, we will quantify actomyosin contractility and biological efficacy of CN03 in a rat IVD puncture injury model. In Aim 2, we will synthesize and characterize an intra-NP drug depot for sustained release of CN03 in rat IVD over a period of 1 month. In Aim 3, we will assess the therapeutic efficacy of CN03 conjugated to Avidin-Dextran in an in vivo rat IVD puncture injury model. Successful completion of these high risk/high reward studies will demonstrate that actoymyosin contractility is an appropriate disease modifying drug target for DD, that Avidin cationic nanostructures can deliver a sustained cargo of a large molecular weight protein up to 1 month in the IVD, and that optimized delivery of CN03 conjugated Avidin-Dextran improves disc functional repair in vivo. These therapeutic strategies are highly translational, and future studies will therefore evaluate these strategies in a large animal model of DD and in treating symptomatic back pain.