ROS scavenging nanoparticles for mitigating oxidative stress in osteoarthritis

项目摘要 氧化应激在骨关节炎（OA）的发病机制中起着关键作用，是重要的治疗靶点。 虽然已经研究了靶向活性氧（ROS）的抗氧化剂或试剂用于治疗 OA，许多已经证明了共同的缺点，如生物利用度和稳定性差，以及快速 关节内注射后从递送载体的关节清除或释放曲线。因此，存在 迫切需要在关节组织内定位和保持治疗水平的抗氧化剂，以保护关节免受 氧化应激的有害影响。该提案探讨了二氧化锰的应用 纳米颗粒（MnO 2 NPs）具有抗氧化酶样活性，可减少OA关节的氧化应激， 解决了小分子抗氧化剂和天然酶的局限性，例如成本和稳定性。此外，本发明还提供了一种方法， 这些纳米材料的性质可以针对组织保留和细胞靶向进行定制，这是重要的 用于解决关节组织中治疗定位和摄取的关键障碍。最近，我们报道了 工程化MnO 2纳米颗粒，用于吸收到软骨中并延长体内关节保留，以及减少 炎症诱导的体外软骨氧化应激。由于其再生能力有限，软骨 特别易受氧化应激的影响，并且代表了关键但具有挑战性的组织靶点。因此，这 该提案的重点是询问MnO 2 NP介导的软骨保护机制，同时测试 MnO 2纳米颗粒在体内疾病模型中的功效。核心假设是MnO 2 NPs将减轻氧化 关节损伤后的压力，预防或延迟OA的发作。在目标1中，我们将研究摄取机制如何 MnO 2纳米颗粒的细胞内定位影响隔室特异性ROS清除和拯救能力， 软骨细胞中的特定抗氧化途径。此外，细胞内靶向与 将确定细胞外滞留对氧化还原信号传导、软骨保护和抗炎作用的影响。 在目标2中，我们将评估MnO 2 NP治疗对体内氧化应激和OA进展的影响， 创伤后OA（PTOA）大鼠模型。我们将全面评估颗粒的功效， 调节体内ROS，减轻OA相关的组织学和生物化学（滑液）变化，和 通过行为测定减轻OA相关的疼痛和残疾。拟议的工作将推进一个新的ROS 清除战略的治疗PTOA，克服了持续的挑战，提供 抗氧化剂拟议的工作还将揭示细胞内递送的关键机制， 软骨细胞以及抗氧化剂递送的位置和时间如何影响疾病机制。机械论 我们在这里提出了一种综合的方法来表征MnO 2 NPs清除ROS的效果 可以促进这种和/或其他抗氧化剂策略对关节损伤的长期成功转化， 疾病

PROJECT SUMMARY Oxidative stress plays a key role in the pathogenesis of osteoarthritis (OA) and is an important therapeutic target. While antioxidants or agents that target the reactive oxygen species (ROS) have been investigated for treating OA, many have demonstrated common disadvantages such as poor bioavailability and stability, as well as rapid joint clearance or release profiles from delivery vehicles following intra-articular injections. Therefore, there exists a critical need to localize and retain therapeutic levels of antioxidants within joint tissues for protection against the deleterious effects of oxidative stress. This proposal explores the application of manganese dioxide nanoparticles (MnO2 NPs) with antioxidant enzyme-like activity to reduce oxidative stress in OA joints while addressing limitations of small molecule antioxidants and natural enzymes, such as cost and stability. In addition, the properties of these nanomaterials can be tailored for tissue retention and cell targeting, which is important for addressing critical barriers to therapeutic localization and uptake in joint tissues. Recently, we reported engineering MnO2 NPs for uptake into cartilage and prolonged joint retention in vivo, as well as reduction of inflammation-induced oxidative stress in cartilage in vitro. Given its limited capacity to regenerate, cartilage is particularly vulnerable to oxidative stress and represents a crucial yet challenging tissue target. As such, this proposal focuses on interrogating the mechanisms of MnO2 NP-mediated chondroprotection while testing the efficacy of MnO2 NPs in an in vivo disease model. The central hypothesis is that MnO2 NPs will alleviate oxidative stress after joint injury and prevent or delay the onset of OA. In Aim 1, we will examine how uptake mechanisms and intracellular localization of MnO2 NPs affect compartment-specific ROS scavenging and the ability to rescue specific antioxidant pathways in chondrocytes. Furthermore, the effects of intracellular targeting versus extracellular retention on redox signaling, chondroprotective, and anti-inflammatory effects will be determined. In Aim 2, we will evaluate the effects of MnO2 NP treatment on oxidative stress and OA progression in vivo in a rat model of post-traumatic OA (PTOA). We will comprehensively evaluate the efficacy of the particles in modulating ROS in vivo, mitigating OA-related histological and biochemical (synovial fluid) changes, and alleviating OA-related pain and disability via behavioral assays. The proposed work will advance a new ROS scavenging strategy for the treatment of PTOA that overcomes persistent challenges with the delivery of antioxidants. The proposed work will also reveal key mechanisms involved in intracellular delivery to chondrocytes and how location and timing of antioxidant delivery impacts disease mechanisms. The mechanistic and comprehensive approach we propose here to characterize the effects of ROS scavenging by MnO2 NPs may facilitate successful translation long-term of this and/or other antioxidant strategies for joint injuries and disease.