Nanoparticle-mediated reprogramming of circulating monocytes and neutrophils to decrease inflammation-mediated damage after trauma

摘要：由于强烈炎症的发展，损伤后组织的再生可能受到限制 可能导致大量细胞死亡和局部环境不当调节的反应， 刺激因子不足，抑制因子过多。我们的长期目标是发展 纳米粒子可以在创伤后重新编程血液中的单核细胞和中性粒细胞的表型，从而导致 改变运输和抗炎表型，减少损害程度，并可能支持 导致增强再生的环境。所提出的研究的前提是基于我们 初步数据表明能够以微创方式递送纳米颗粒 血液中的炎症单核细胞和中性粒细胞重新编程其功能，从而导致大量 脊髓模型的功能恢复。这些颗粒可以通过多种机制增强恢复， 包括减少损伤处的免疫细胞积累、调节脾微环境 已知可协调炎症反应，或直接诱导抗炎或促再生 受伤时的环境。以下目标采用与单核细胞具有差异结合的纳米颗粒和 中性粒细胞，影响其表型，例如运输和细胞因子的产生。重要的是， 重编程仅由纳米颗粒的物理化学性质（例如尺寸、电荷、 成分）且不涉及已停产的活性药物成分（API） 由于风险收益比，许多应用中都没有。本文的重点是确定该机制 颗粒正在增强功能恢复，这也可以确定更有效的设计参数。 目标 1 将研究纳米颗粒与循环中的先天免疫细胞的关联，以及它们的后续作用 炎症反应中的运输和表型。 SCI 后注射纳米颗粒导致 显着的恢复收益我们的目标是确定颗粒促进恢复的机制。 诱导单核细胞和中性粒细胞差异结合、表型极化和运输的颗粒 将被调查。目标 2 将研究重新编程的免疫细胞对微环境的影响 在脾脏和脊髓内。在整个恢复过程中首先对基质细胞和免疫细胞进行研究，并且 随后我们研究了轴突生长、髓鞘形成和功能恢复的程度。总的来说，这些 研究将确定纳米颗粒特性、免疫调节和能力之间的关系 环境以减少损害并增强功能恢复。我们建议粒子 基于其理化特性的重新编程有可能成为一种转化疗法 通过提供一种现成的、非侵入性的方法来重新编程炎症单核细胞来减轻创伤， 中性粒细胞以限制损伤并增强再生。

Summary: Regeneration of tissues following injury can be limited due to the development of strong inflammatory responses that can lead to substantial cell death and inappropriate conditioning of the local environment, which becomes deficient in stimulatory factors and has an excess of inhibitory factors. Our long-term goal is to develop nanoparticles that reprogram the phenotype of monocytes and neutrophils in the blood after trauma, resulting in altered trafficking and anti-inflammatory phenotypes that reduce the extent of damage and may support an environment that leads to enhanced regeneration. The premise of the proposed research is based on our preliminary data indicating the ability to deliver nanoparticles in a minimally invasive manner that target inflammatory monocytes and neutrophils in the blood to reprogram their function, which leads to substantial functional recovery in a spinal cord model. The particles may enhance recovery by multiple mechanisms, including reducing immune cell accumulation at the injury, modulating the splenic microenvironment that is known to coordinate inflammatory responses, or directly inducing an anti-inflammatory or pro-regenerative environment at the injury. The following aims employ nanoparticles with differential binding to monocytes and neutrophils, which influences their phenotype such as trafficking and cytokine production. Importantly, the reprogramming is mediated solely by the physicochemical properties of the nanoparticles (e.g., size, charge, composition) and does not involve an active pharmaceutical ingredient (API), which have been discontinued from many applications due to the risk-benefit ratio. The focus herein is to identify the mechanism by which the particles are enhancing functional recovery, which may also identify design parameters that are more efficient. Aim 1 will investigate nanoparticle association with innate immune cells in circulation, and their subsequent trafficking and phenotype in the inflammatory response. Nanoparticle injection following SCI has led to substantial recovery gains we aim to identify the mechanisms by which the particles are promoting recovery. Particles that induce differential binding, phenotypic polarization, and trafficking of monocytes and neutrophils will be investigated. Aim 2 will investigate the impact of the reprogrammed immune cells on the microenvironment within the spleen and spinal cord. Stromal and immune cells are initially investigated throughout recovery, and we subsequently investigate the extent of axon growth, myelination, and functional recovery. Collectively, these studies will determine the relationship between nanoparticle properties, immune modulation, and the capacity of the environment to reduce damage and enhance functional recovery. We propose that the particles that reprogram based on their physicochemical properties have the potential to be a transformational therapy for trauma by providing a readily available, non-invasive means to reprogram inflammatory monocytes and neutrophils in order to limit damage and enhance regeneration.