Systemic Application for Injury Site Specific Delivery via Neutrophils to Treat B

描述（由申请人提供）：腰痛是一种地方性问题，是美国人去看医生的第二大常见原因，仅次于最常见的感冒和流感。腰痛也是缺勤的第二大常见原因，也是导致残疾的最常见原因。近年来，大量研究表明，损伤性炎症可能在椎间盘受损和退变引起的腰痛中起作用。因此，自20世纪50年代开始作为一种治疗方法以来，使用透视引导下的腰椎硬膜外注射类固醇来减少局部化学炎症反应的使用急剧增加。然而，硬膜外注射的风险包括但不限于硬膜外血肿、硬膜外感染、神经根损伤、硬膜穿刺、空气栓塞和血管迷走神经性晕厥。此外，硬膜外注射在技术上要求很高。通常由受过特殊训练的医生在x光下进行。当病人得到预约时，疼痛可能处于亚急性或慢性状态。因此，对急性/慢性背痛进行经济有效的治疗是非常重要的。我们的申请提出了一种新的治疗方法，将纳米富勒烯与cFLFLF连接，以特异性靶向迁移到椎间盘突出部位的活化中性粒细胞，并通过外周静脉注射治疗腰酸背痛，这在技术上要求不高，可以由护士进行。纳米富勒烯具有强大的抗氧化和抗炎特性，无需特异性生物靶点，不仅可以减轻椎间盘突出髓核组织挤压引起的痛感，还可以消除标准生物靶向药物分子的副作用。然而，需要一种有效的递送系统来克服其高度疏水性，以特异性靶向损伤部位。本研究的总体假设是，表达甲酰基肽受体（FPR）的活化中性粒细胞与具有蛋白水解抗性的合成肽cFLFLF结合，并共同浸润和积聚到疝疝的炎症部位。将纳米富勒烯连接到cFLFLF （cFLFLF- peg -富勒烯）将确保抗炎剂通过全身注射到达损伤部位的事件特异性时间和空间递送

DESCRIPTION (provided by applicant): Low back pain is an endemic problem and is the second most common reason that Americans go to see their doctor, second only to the most common cold and the flu. Low back pain is also the second most common illness-related reason given for a missed workday and the most common cause of disability. In recent years, a body of research has suggested a possible role of injury-induced inflammation in low back pain caused by damaged and degenerating intervertebral discs. As such, the use of fluoroscopy-guided lumbar epidural injections of steroids to reduce the local chemo-inflammatory response has increased dramatically since their inception as a treatment in the 1950s. However, the risks of epidural injections include, but are not limited to, epidural hematoma, epidural infection, nerve root injury, dural puncture, air embolism and vasovagal syncope. Moreover, the epidural injection is technically demanding. It is usually performed under x-ray by doctors with special training. When a patient gets an appointment, the pain is likely in a more subacute or chronic state. Therefore, a cost-effective treatment for acute/chronic back pain is of great importance. Our application proposes a novel treatment by linking nano-fullerene to cFLFLF in order to specifically target activated neutrophils that migrate into the disc herniation site and treat acut back pain via peripheral vein injection, which is not technically demanding and could be performed by a nurse. Nano-fullerene, which has potent anti-oxidative and anti-inflammatory properties, without specific biological target could not only reduce hyperalgesia induced by the extrusion of nucleus pulposus tissue from herniated discs, but also eliminate the side effects associated with standard biological target-oriented drug molecules. However, an effective delivery system is needed to overcome its highly hydrophobic properties to specifically target the site of injury. The overall hypothesis of this study is that the activated neutrophils expressig formyl peptide receptor (FPR) will bind to proteolytically resistant synthetic peptide cFLFLF and that together they will infiltrate and accumulate into the site of inflammation in the herniated dic. Linking nano-fullerene to a cFLFLF (cFLFLF-PEG-fullerene) will ensure event-specific temporal and spatial delivery of the anti-inflammatory agent to the site of injury via systemic injection to treat the pain caused by excessive inflammation in and around herniated discs. In Aim 1 of the proposed study, we will characterize the infiltration of activated neutrophils into an acute disc herniation using neutrophil-specific small molecule imaging agents and immunohistology. The imaging signal will be validated using FPR knockout mice. The neutrophils and macrophages will be analyzed for expression and quantification of FPR and for the quantification of injury. In Aim 2, we will characterize the inhibitory effect of aqueous suspensions of nano-fullerene on local inflammation induced by disc herniation in vitro and in vivo. In Aim 3, we will synthesize cFLFLF-PEG-fullerene and evaluate its systemic vs. local delivery to a site of inflammation in a mouse radiculopathy model; we will also assess injury site target systemic delivery vs. non- specific systemic delivery using wild type and FPR knockout mice in a disc degeneration model induced by needle puncture. This study will provide useful insights into a novel cost-effective therapeutic strategy for acute and chronic back/neck/leg pain involving systemic injection of non-protein, nano-structured, biocompatible fullerene conjugated with cFLFLF, a neutrophil-specific binding peptide. This method is much more cost- effectiveness compared to epidural steroid injection.