Novel Carbon Nanozyme Mechanisms for Traumatic Brain Injury

翻译后摘要：在前一个资金周期，我们成功地获得了化学基础的机械理解 对于我们的碳纳米颗粒（CNP）平台在轻度创伤性脑损伤（TBI）中的优异治疗作用， 聚乙二醇-亲水性碳簇（PEG-HCCs）。我们确定了新的行动， 新的发展方向我们：1）发现HCC的宽氧化还原电位延长了它们的作用， 参与电子传递的线粒体成分中的氧化还原介体，即纳米颗粒酶，或 “纳米酶”，和2）确定了一种新的机制，出血引起细胞毒性：快速和 持续产生DNA双链断裂和强大的DNA损伤反应，导致细胞 “衰老”，其中细胞成为炎症的病灶。而PEG-2能延缓衰老， 在HCC中，细胞变得对铁毒性/铁凋亡敏感。这种相互作用使我们产生了一种新的CNP， 共价键合铁螯合剂，去铁胺（DEF）。我们的结果表明，DEF-HCC-PEG有效地 论述了氯化血红素和铁相关的损伤、衰老和铁凋亡。考虑到线粒体功能障碍和 出血性挫伤（HC）与TBI的不良结局相关，这些发现直接表明了 去追求这些机制。我们的CNP平台的关键机制特征的识别， 线粒体作用位点和新的损伤诱导病理机制形成了这一基础 续期申请。我们将结合我们对PEG-HCC作用机制的理解， 采用良好生产规范（GMP）起始物料的更直接可转化CNP，活化 活性炭，并在具有出血性挫伤的啮齿动物TBI（TBI/HC）中进行体内测试。我们的总体假设 在我们之前的申请中发现的作用机制将可转化为GMP起始物料 并将作用于与TBI/HC相关的基因组和线粒体损伤。具体目标1将测试 假设氧化合成环境可以被优化以产生GMP衍生的起始物质， 材料，PEG-氧化活性炭实现CNP纳米酶的所需特性。具体 目的2将检验DEF-连锁CNP将解决衰老相关线粒体和基因组损伤的假设。 引发衰老和抗铁凋亡的事件。具体目标3将管理制定的国家方案 在目的1和2中，对中度-重度TBI/HC模型。实现这些目标将更容易产生 我们的CNP平台的可翻译版本建立在对关键功能和网站的日益了解之上， nanozyme机制。新的治疗靶点从更深入的了解中出现 出血使TBI结果复杂化的病理机制将指导设计。通过 采用GMP起始材料，该项目可以更快地产生突破性材料， 诊所因为线粒体功能障碍和出血的细胞后果都是 急性损伤和老化和认知能力下降，这种疗法的更广泛的潜力建议。

Abstract: In the prior funding cycle, we successfully obtained a mechanistic understanding of the chemical basis for the excellent therapeutic actions in mild traumatic brain injury (TBI) of our carbon nanoparticle (CNP) platform, poly(ethylene)glycol-hydrophilic carbon clusters (PEG-HCCs). We identified new actions that point to profound new directions for our CNPs. We: 1) discovered that the HCC's broad redox potential extended their action as a redox mediator among mitochondrial constituents involved in electron transport, i.e. a nanoparticle enzyme, or “nanozyme”, and 2) identified a new mechanism by which hemorrhage causes cellular toxicity: rapid and persistent generation of DNA double strand breaks and robust DNA damage response leading to cellular “senescence”, in which cells become a nidus for inflammation. While senescence could be prevented by PEG- HCCs, the cells became sensitized to iron toxicity/ferroptosis. This interaction led us to generate a new CNP, covalently bonding iron chelator, deferoxamine (DEF). Our results indicate DEF-HCC-PEG effectively addressed hemin and iron-related injury, senescence and ferroptosis. Given that mitochondrial dysfunction and hemorrhagic contusion (HC) are associated with poor outcome in TBI, these findings directly indicate the benefit of pursuing these mechanisms. The identification of key mechanistic features of our CNP platform that facilitate a mitochondrial site of action and new mechanism of hemorrhage-induced pathology form the basis for this renewal application. We will incorporate our understanding of the PEG-HCC mechanisms of action to generate a more immediately translatable CNP utilizing a good manufacturing practice (GMP) starting material, activated charcoal, and test them in-vivo in a rodent TBI with hemorrhagic contusion (TBI/HC). Our overall hypothesis is that the mechanisms of action discovered in our prior application will be translatable to GMP starting materials and will act on both the genomic and mitochondrial damage associated with TBI/HC. Specific Aim 1 will test the hypothesis that an oxidizing synthesis environment can be optimized to generate GMP-derived starting materials, PEG-oxidized activated charcoal achieving, the desired characteristics of a CNP nanozyme. Specific Aim 2 will test the hypothesis that DEF-linked CNP will address hemorrhage-related mitochondrial and genomic events triggering senescence and resistance to ferroptosis. Specific Aim 3 will administer the CNPs developed in Aims 1 and 2 to moderate-severe TBI/HC model. Completion of these Aims will yield a more readily translatable version of our CNP platform building on a growing understanding of the critical features and sites of action for their nanozyme mechanisms. New therapeutic targets emerging from a more thorough understanding of pathological mechanisms by which hemorrhage complicates outcome from TBI will guide the design. By employing GMP starting material, this project can generate breakthrough materials more rapidly translatable to the clinic. Because mitochondrial dysfunction and the cellular consequence of hemorrhage are features both of acute injury and of aging and cognitive decline, a broader potential for this therapy is suggested.